riddle.

One question, and you only need one robot of any type:  "If I were to ask
you whether the left door leads to freedom, and you chose to
answer that question with the same degree of truth as you answer this
question, would you then answer 'yes'?"

The truthteller will say "yes" if the left door leads to freedom,
and "no" otherwise.  The liar will answer the same, since he will lie about
where the left door leads, and he will lie about lying.  The randomizer
may either lie or tell the truth about this one question, but either way
he is behaving like either the truthteller or the liar and thus must
correctly report the road to freedom.

If however the third robot randomly answers yes or no it is clear that
you must ask at least two questions, since you might be asking the
first one of the randomizer and there is nothing you can tell from his
answers.

Start by asking A "Is B more likely to tell the truth than C?"

If he answers "yes," then:
   If A is truthteller, B is randomizer, C is liar.
   If A is liar, B is randomizer, C is truthteller.
   If A is randomizer, C is truthteller or liar.

If he answers "no," then:
   If A is truthteller, B is liar, C is randomizer.
   If A is liar, B is truthteller, C is randomizer.
   If A is randomizer, B is truthteller or liar.

In either case, we now know somebody (C or B, respectively) who is
either a truthteller or liar.  Now, use the technique for finding
information from a truthteller/liar, viz., you ask him the following
question:  "If I were to ask you if the left door leads to
freedom, would you say 'yes'?"

If the answer is "yes," take the left door, if "no" take the right door.

If you just want to identify the three robots, there are several ways to
proceed.  Perhaps the simplest is to ask the robot identified as either a
truthteller or a liar some question like "Is one plus one equal to
two?"  If he answers "yes," then he is the truthteller, else he is the
liar.  If he is the truthteller, ask him if another robot is the liar.
By process of elimination you know the identity of the third robot.  If
he is the liar, ask him the same question, but disbelieve the answer.
Then again by process of elimination you know the identity of the third
robot.



H4gg0n

Here is another one: You order the robots to open both doors and tell one to go in each door. If the robots are smart, they will not dare to go in the room with the fiery death, whether they are liars or not. Even if they do, having a robot standing in front of you is a great way to block any attacks the enemy may throw at you.

I am really trying hard here...

can't you open the door and look?

"If I were to ask the other robot which door led me to freedom what would he say" and you walk in the door OPPOSITE of what the robot tells you

Lets denote them as ROBOT A and ROBOT B, and door 1 is death and door 2 is life

If you ask ROBOT A and if ROBOT A tells the truth he'll say that the other robot will say door 1
If you ask ROBOT A and ROBOT A is the liar he'll say the other robot will say door 1

BOTH WAYS you go through the other day which is life

theProfessa - you missed the part about three robots, not two
ozo - I'm unable to access the link, care to revisit that?
gedmac - there's no guarantee here that any robot knows much of anything worth asking about
phileoca - my own preference is to avoid (control) the problem from earlier on in the game (escape etc prior to facing robots or doors)
Sid_The_Kid - we've done such questions before, and, given the invalidities, my temptation is to alter the tack, and this time I'd use the robots, so rather than describe it, concerning your 2nd suggestion:

I Ditto Sid_The_Kid (#2)

"Will you kindly help me to escort the other two robots out this door"
[maybe point at one door, but stand closest to the other]

http:#15526489 was essentialy a repost of the link
whatever the robots may know, the question states that they will either lie or tell the truth.

The original link I posted seems to be broken at the moment.  The same answer be found at
http://www.faqs.org/faqs/puzzles/archive/logic/part4/
http://brainyplanet.com/index.php/Fork%20Three%20Men

It is amazing how much sheer brainpower we ascribe to robots and liars. Considering that a lie is the 'easy answer' how about this:

You are standing on a subway platform waiting for the train to Hoboken when somebody approach you and ask:

Q: "If I were to ask you whether the next train go to Queens, and you
    chose to answer that question with the same degree of truth as you
    answer this question, would you then answer 'yes'?"

Which of the following answers would you give:

A1: Huh ?
A2: Yes !
A3: No !
A4: You got some nerve calling me a liar, you ... <whack whack whack>

regards JakobA

Real people, unlike puzzle robots, are not constrained to either lie or tell the truth.
I'm sure we can all point to our favorite exapmple of this in the headlines.

Maybe I've seen too many movies or read too many books, but I thought that it went that robots need a bit more precision in facts, and more often provide lengthy responses than simple one word answers like yes or no, so at the moment I like response of JakobA and the first of Sid_The_Kid best, with the 2nd comment above the least as it seems to be missing the part of crediting original author. Me try again.. where answer to typical questioning would go...

Robot A: I dunno
Robot B: A safe door is like a safe passage to a safe house, in that once you use it it can no longer be considered safe, so if it is a door which will become less safe at a later date, then it should be considered less safe in the present than you might otherwise think, in which case .... (on and on through various permutations of possible outcomes)
Robot C: Would you like to play a game of chess?

Answer: Ask the robot to handle your enemies for you as your personal escort back the way you came in

Ask..    "If door one is safe, what door is safe.”

If door one is safe, what door should I go through?

No .. Ask how many safe doors are on the left.

No Ask how many doors on the left are safe!

Who's left?

noone is safe

isn't asking a 'double' question sort of like cheating? I'd consider any question with an 'if' to be a double question... even if there's only one (verbal) answer and the other is an action...

I'm afraid I don't know the right question either, given that constraint. Without the constraint, you can basically ask any number of questions by just combining them into one sentence/order.

Merging multiple boolean 'AND' + 'OR' can introduce interesting results the longer those sentences go. It also helps to have multiple individuals involved, then refer to each and all with pronouns.

Is this one of those trick questions with no possible answers, if so, I would like to be the first to suggest the answer is: There is no way of asking one question into three robots and getting one definite answer, if one robot tells lies, one tells truths, and the other tells half-truths. Even using the "double questions" above, say "answer that question with the same degree of truth as you answer this question" (JacobA) the half-truth robot could think of the truthful answer, and then lie about the degree of truth – inverting his spoken answer into a lie. Essentially, the half lying, half-truth telling robot is just a random answer generator. Therefore there is no way whatsoever to get an answer above a 50% chance of being true from the sum of these robots by asking them any 1 question. Lets say the truth teller and the liar were left out and you were asking your question to a robot that sometimes lied and sometimes tells truths. There is no way…  I can though tell you the minimum amount of questions you would have to ask to the three robots to get a definite answer. All you need to do is ask, “What is 1 + 1?” After asking about 2 times, if you are lucky you will have identified the lying robot OR the truth telling robot. 3 times, and if the robots answer in just the right order, you would have identified all three robots for who they are (it is fairly complex to explain how this works). Then you must ask which door leads to the exit, until either the lying robot or the truth telling robot answers. So that’s a min of 4 questions – and a max of positive infinity. But here is the bonus – if you identify the truth teller, you can destroy the other two robots to that only the truth teller can give you answers. That means having asking less questions and getting unpredictable answers.

Or is this one of those questions that you are going to ask but never tell us the answer and never award the loot? Grrrrrrrrr.

there is definitely an answer, Sid...

I say minimum 2 questions, with a lucky first answer
First question. Ask "Does the robot who answers this question lie?"
If the robot answers yes, then you have just identified the random robot.

2nd question. Ask "Which way does the robot who did not answer the last question, and will not answer this question say is the door to a FIERY death?"

If either of the other 2 robots answer, pick that door.

Now question is, can the first robot answer the 2nd question? I'm not sure about that one. I claim no.

Wait, are we still assuming "a random robot will answer." ?

Also in my solution, change the first question to, "Which robot always lies?"  If the robot answers himself, we've identified the random robot. But if he doesn't answer himself, we get a little more info on the situation.

MizzL > there is definitely an answer, Sid...

Agree/Disagree.
(1) For such a question, typical 'acceptable' answer given (this is the agree part). Besides, that is a cornerstone of this TA compared to others, it should be the only one where asker knows answer in advance.
(2) Since a greater majority here either do not acknowledge answer, or do not accept it, it cannot be considered valid (this the disagree part)

Answers should be agreeable, and acceptable, once revealed. So I think non-traditional form of answer is more applicable in such cases.

> the other tells half-truths
no, the other "might lie, or might tell the truth"
this is a subtle but critical difference.

> So that’s a min of 4 questions
If telling half-truths was an option in addition to lie or tell the truth,
then two questions would be necessary and sufficient.
One question to identify a robot that does not tell half-truths,
and another question for a reliable robot.

A problem can remain in how to line up the parentheses in a compounded question using the english language where ambiguities set in so quickly it is dificult to get people of equal knowledge and experience to agree on what is meant. On the downslide, I also think such questions are too unreal, such as for expectancies (will anyone answer) and information flow (who knows what, and how many assumptions are there, such as introducing right and left).

That said, a potential 'out' could be had, that I do not see above, is by not asking robot to figure out what answer they'd give, if they were asked, but what answer the truth-teller robot would give. To fix the directional problem, point at the door yourself. None of this means that any robots are omniscient. Similar problems are not changed by making them monks instead of robots, and use of pronouns increases ambiguity.

> no, the other "might lie, or might tell the truth"

or might not know, might not answer, might have a different way to answer, might get confused about the question <heh> take that one out early, by making it go into a loop where it identifies itself by all the smoke coming out its ears. Do they have ears? Can they talk? What language? Binary? Morse code?

How about, rather than ask, just blurt out a statement and watch it evolve. Something like:

"Fire!"

-or-

"This room is going to self destruct in 30 seconds and eliminate all who remain here that long"

"We have to all get out of here before the bandits and used robots parts dealers show up, we've got about 20 seconds"

> this is a subtle but critical difference.

agreed

I think the answer given by H4gg0n works though it does have the added complexity of a compund double question "If A and B".  Here is a workable solution that only asks the robot to give an answer to a single question that would be asked of another robot.

According to this question the third robot does not randomly answer the question but randomly decides to answer the question truthfully or not.  Its answer is then dictated by that decision.  This is just a variation on the original version of the quesiton.  The introduction of the random liar/truth teller doesn't really change the question that gets the correct answer.

My assumption is that the random robot will apply the decision to lie or not to the final answer to the question put to it as asked.

The question:  If I were to ask a robot who answers the question in the opposite truthfullness from how you would answer the question which door leads to safety which door would he choose?

With only two robots this is the well known answer.  It also works for the third robot.  If that robot will answer the question falsly then the other robot to ask would be the truth teller who would give the correct door thus this robot would give the wrong door.  If instead this robot will answer truthfully then the other robot to be asked would be the liar who would give the wrong door thus this robot will turthfully give the wrong door.  In all cases you will take the other door from the one any of the three robots offer.

All adding the random robot adds to the problem is having to be more specific about who is being asked what.

What if you didn't ask a robot a question. What if you just said to any robot, "Take me through the door to freedom", you aren't asking any robot to tell a lie or tell the truth, you a commanding them to perform an act.

Or alternatively you could ask a robot, any robot, "Ask the robot who tells the truth to take me through the door to Freedom"


FoxCon

Say to ALL the robots: "Go throught that (pointing randomly) door, walk around a bit and then come back."
Then go through
either   the door a robot came back through
or        the door opposite the one no robot came back through after 5 minutes.

All of these suggestions have already been made.

GnarOlak > how you would answer the question

"the cat is not"

 Sid_The_Kid,
just goes to show you how 'acceptable' and 'agreeable' are so many supposed 'answers' to logic problems that try to compound gates and lose sense of time and individuality (reality)

(although I forgot if I admitted, to asking such a question in EE myself)

http://www.experts-exchange.com/Miscellaneous/Puzzles_Riddles/Q_20437461.html
asked by SunBow on 12/27/2002 Title: Fork  U
This solution was worth  20 Points

<ugh> an embarassing one, prior to split pointing and point increasing, and some of the menu options to help find threads, times of "points for..." (uncool), but ... inattentive too long, booey on me. But apparently six similar spin-off questions followed as well, most of 'em likely resolved as well.

http://www.nickvautier.com/puzzles/

in this link is the real problem, there is no a third robot that might tell the truth or might lie. There are only two robots.

"My dear robots, I have a question for you, but first I need to address this situation of imperfection in human assembly plants, and as two of you are defective, I'd like the one who always tells the truth to disable the other two, and then to lead me through the 'safe door', whereupon I will ask you a very important question about resolving a riddle"

Is my left to my right or my right to left where I left the right of lefts? ANSWER

asl a robotto walkthrought door A. If he is fried go throught door B.If he lives use door A.

to borrow from a similar scene in the movie, the 10th kingdom, you ask a robot "what the hell kind of stupid question is that?" and while it ponders your question, you chuck (in the movie it was a toad, so with a robot you might need to push, not chuck) it through the nearest door. if it falls to a horrible death, go through the other door.

Yeah but there is no way of knowing how far down the hall through the death door you need to walk before the horrible death occurs, it could be 10 km down the hall!

If the lying robot really behaved this way, Spaceman Sid could simply ask "which door do I take?" and all robots would point to the right door. But clearly the lying robot would not behave that way; therefore your theory is flawed. To lie to the question "Which door should I not take?” the robot would need to point in the direction of the door that he should take - whether or not they actually pointed with their hands or said "Take the left/right door".

Hi Sid_The_Kid,

I think you misunderstood me.

If he were to ask :"which door do I take?", then the lying robot would be able to say (not necessarily point):"you should not go ths way" because its a lie.

But if he were to ask :"which door do i not take?", then the lying robot wouldn't be able to say:"You should not not take(means - you should take) the door leading to a fiery death" because its a truth (saying:"You should take this door" is an implied truth).

Anyway, lets wait and see the author's and others' comment on my theory.

Cheers

Sorry,
I made a mistake.
*But if he were to ask :"which door do i not take?", then the lying robot wouldn't be able to say:"You should not not take(means - you should take) the door leading to freedom" because its a truth (saying:"You should take this door" is an implied truth).

I'm sorry

Regards,
bk_jreinstein

What about "Which door would the lying robot tell me to take?"  The truthful one will point to the bad door.  The lying one would have said to take the bad door, but lying about it, would point to the good door.  But he must also lie to cover up being the lying robot and so points to the bad door.  The random answer one will give either of these answers, which happen to be the same.  So Sid should take the other door.

Hi Aramis 11!

Your just adding another layer to my answer(good one).

Now, I'll explain why your answer is the same as mine:

"Which door should I not take?"

                      IS

Same as asking the answer of the lying robot since the lying robot would tell me which door not to take when asked.

Regards,
bk_jreinstein

The trick is  to make all the robots point to the same door.

But, if you are able to make the truth robot and the lying robot point to the same door, the unpredictable one does not matter as it will act only as the truth robot or the lying robot and the answer will eventually be the same.

I have a BIG CORRECTION to make.

Pls see next post.

Regards,
bk_jreinstein

I'm totally revising my answer and this just struck me after I posted a comment on similarity of our answers to Aramis11. Our answers have a catch to them, there is another question to be asked without using 2 questions.

The true way of going about this is to build a 'dobule question', i.e., a question whtin a question, an dit goes like this-

"If I were to ask you which door should I not take, which door would you point to ?"

Now take the stragihtforward question contained within this question statement- "Which door I should not take?"

The truthful robot would, in response to this, point (or direct in anyway) to the door that leads to death; whereas the lying robot would point (or direct in anyway) to the door that leads to freedom.

Now, since the main question is in effect- what would be your response?, the response of the robots to this would be as under-

The TRUTHFUL ROBOT would say, "I would point to this door." (we know that the door referred to here is the door leading to death because of the the question)

HOWEVER, the LYING ROBOT in order to ensure that it lies about its response to the simple question contained within, is also supposed to say, "I would point to this door."(we know that the door referred to here is the door leading to freedom.
But it cannot say, "I would point to this door (referring to the freedom door because thats what it would really point to)" because its a truth so, it would say the same referring to the door leading to a fiery death).
Now, both the robots say the same sentence and both are referring to the death door.

Hence in either case, the response of either robot, or even a robot that would at times lie, and at times tell the truth- would always be to indicate the door leading to death.  

Quite simply, you then go through the other door- and to freedom!

Hope I wasn't too confusing  :-)
Regards,
bk_jreinstein

Not confusing, just repackaging the added layer.  The whole point of asking not about the doors but what the robot would say was to get the same three answers.  So first you tried to explain why this answer (04/06/2006 03:53PM EDT) was the same as your preceding one, then told why the answer works, and then put a new coat of paint on it.  It may still be wrong but looks like the only shot at getting out alive with only one question.

No, Aramis.

The last answer of mine, and yours(which was the same adding a layer) was wrong because the if lying robot was asked which door not to take then it WOULD be lying to the QUESTION by telling the freedom door so anyway it WILL tell the freedom door, the truth robot will tell the death door so it doesn't get us anywhere.

But in my revised version, it HAS TO LIE TO THE SECOND QUESTION TOO (which door would you point to?)
Thats why it will have to say that it would point to the death door.
So, both say the same in my second version ONLY.

Regards,
bk_jreinstein

ummm................... gedmac?

Yes, it is essentially the same answer as http://brainyplanet.com/index.php/Fork%20Three%20Men%20Solution
"If I were to ask you whether the left fork leads to Freedom,
and you chose to answer that question with the same degree of truth as
you answer this question, would you then answer 'yes'?"

Now that answer (ozo 04/09/2006 05:52PM EDT) really is different.  No doubt we will soon see a claim that it is a clone to a previous answer, but needs to be dressed up with some subtle nuance and then presented as the real one.  Ah, but in this one Sid specifies a door and selects it upon an affirmative reply.  This may need about twenty coats of lacquer.

I think bk_jreinstein takes an interesting side-step to this question; by changing the format in which the robots answer. Indeed, since we have not been told how the robots would answer, it leaves this possibility open.

However, most of the posts beforehand assume:
1. If asked a truth question, robots will answer "Yes" or "No".
2. If asked a door question, robots will respond by indicating a certain door.
3. If asked a robot question, robots will respond by indicating a certain robot.

Making those assumptions, I think the random robot throws a wrench in bk_jreinstein's plans.

Still say minimum 2 questions.

jkmyoung,

It cannot effect the answer if any robot is to answer (read my revised version again). If you read it, please post your arguments freely I'll ry to find answer to every oneof them.
And yes there are 2 questions, but I made both questions in 1 question.

Regards,
bk_jreinstein

Effect?  It may be sufficient to compose a question that will get a useful answer from a truthful robot but cause a lying one to seize or explode from processor overload.  It could be something like, "Would you be lying if you told me that I can safely escape through the left-hand door?"  [Would at least have literate credibility.]

Sorry, by random, I meant the possibility that the 3rd robot (who sometimes lies and sometimes doesn't) would answer. Now if that robot were asked which door it would point to, it would sometimes point to one door and sometimes to the other door. So, when asked which door it would not point to, it could:
point to freedom door and be lying
point to freedom door and be telling truth
point to death door and be lying
point to death door and be telling truth

I think Aramis has an interesting idea, although I would revise it to composing a question that a truthful or lying robot could answer, but a robot whom told both truth and lies could not answer.

It was not by accident the phrasing was 'a' lying robot, to apply also to the random one when it is in a lying mood.  Thinking on it further, that last idea has a pitfall.  If the machine was running C code, for example, it would evaluate the expression "Would you be lying if" and throw the rest out as inconsequential.  A lying one, knowing it will be lying regardless of the subject, will answer "No", divulging nothing about the portals.  It could possibly fail in any case and even may glean a faulty (to Sid) answer from the truthful robot.  

Sorry, I answered on my brother's id.

It does not seem like anyone's id, or any aspect of psychology for that matter, would be of much use in dealing with robots.  This looks like more of a logic and semantics problem.

I meant I had answered from my bro's email id last time

gedmac?

I'm done trying.

You ask one question and can receive two answers; the truth or a lie.

Since a random robot answers, you must consider the answer as if it came from any or all of them.

Simply,
+ - + = -
or
+ - - = +

Asking an n-tiered (where n is any positive integer) question does not work because the answer could possibly be filtered through an unpredictable responder.

BTW, if this problem does have a logical answer (as opposed to some semantics loophole), I would expect a lot of EE subscribers to begin winning the lottery. If you can query a random element and receive a answer on which you can act with 100% assurance, everything becomes predictable. If there is a loose thread in the universe, this riddle is the hand that will unravel it.

Alright, the question has been answered. Here is my logic for this conclusion based on pedalhead mathematical model. The idea is for all the answers from all the robots to = +

By asking a stright forward Question: "Which door = safety?"
Truth: +
Lie: -
Random Truth/lie: + OR -

Therefore it does not work

By asking my first double Question: ""If you were a robot that only answers in lies then which door would I need to take to get out of here, If you did not tell the truth, then do not indicate that you are lieing, otherwise, do, but after you give your initial answer."
Truth: + AND sqrt(-1) = +
Lie: - AND - = +
Random Truth/lie: (+ AND (- OR sqrt(-1))) OR (- AND (+ OR -)) = Random + OR -

Therefore it does not work, I must admit, because of the unpredictable nature of the random robot. And also there is no way to tell whether the robots will actually even think about indicating whether they are lieing or not. So no more "double questions" will be used for these examples.

Here is one from theProfessa: "If I were to ask the other robot which door led me to freedom what would he say" This question applies to 2 other robots, therefore 2 answers will be given.
Truth: + AND unpredictable +
Lie: - AND unpredictable -
Random Truth/lie: (+ AND +) OR (- AND -)

Therefore that does not work, but almost, the ransom robot throws everything off. It would work for 2 robots

This is getting a bit confusing, lets cut to the chase: "If I were to ask you which door should I not take, which door would you point to ?" by bk_jreinstein But lets revise it a little:

"If I were to ask you which door leads to freedom, which door would you point to?"

Truth: + AND + = +
Lie: - AND - = +
Random Truth/lie: (+ AND +) OR (- AND -) = +

Therefore this one works.

Lets go through this here:

2 parts to the question, and yet it is still a single question and so it will work fine with the random truth/lie robot.
1) Which door leads to safety,
2) Which door is your answer to #1?

Truth:
1) Thinks of which door is safe: +
2) Tells whuch door is safe: +

Lie:
1) Thinks up the lie of which door is safe (so thinks of the bad door): -
2) Lies about which door he would have said (meaning the door above, so he poits towards the safety door): -

Random Truth/lie:
See Truth = ++ = +
Or See Lie = -- = +

Therefore that works fine, and Spaceman Sid just takes whatever door they tell him is safe one.

OK, there is one hole. What if the random robot lies to the first part of the question then tells the truth to the second part?

You are presenting the robot with a question that has two logic gates. Nothing in the question states the robot has to answer consistently just because you only used one question mark. Restating my earlier point, the robot isn't random if one can count on it lie or tell the truth consistently; even if only twice in a row.

>> What if the random robot lies to the first part of the question then tells the truth to the second part?

Rubbish.  There is no detail in the riddle that suggests the random-answering robot will alternate veracity within /portions/ (fake italics) of a question.  A required element of the solution is a single question, which is what you have.  With this question given, there is effectively (functionally) no distinction between the random-answer robot when lying and the lying one.  The solution works because the answer does not depend on which robot of the three answers.

I counter that there is no detail in the riddle that suggests that the random robot would evaluate two logical statements consistently just because they are encapsulated in one question. Perhaps I am being too picky, if there is a solution to the puzzle, the three of you have certainly found it.

The riddle does not say anything about the random-answer robot's logical processes or that it will sometimes lie to itself while working out an answer.  It only says that it will either lie or tell the truth, and this has to be about what it would say if answering your  question.  Your "If I were to ask you which door leads to freedom, which door would you point to?" solution appears to work without any "degree of truthfulness" complication thrown in.  The only real snag may be if the robots are in the form of blank spheres with no appendages, it risks the answer being "Neither", or something like "The door to my left".  It may be impossible especially in zero gravity to discern the robot's physical orientation to the doors.

I think that this riddle is based on robots with highly advanced AI; therefore their physical orientation to the doors should not be of any concern. The robots know what you mean; do you know what I mean?

"With this question given, there is effectively (functionally) no distinction between the random-answer robot when lying and the lying one. "

These are 2 different questions though with regard to a random-answer robot:
What would you do...?
What would a lying robot do...?
"What would you do" to a random robot is not a pure logical statement.

And why isn't it ?

The riddle does not say anything about advanced AI, or fuzzy logic, or guessing what an illogical human really means.  Especially in this type of forum, there should abound an awareness that a machine, e.g., a computer, does not necessarily do what a user wants it to do, but rather only what it is forced to do.  

If the robot cannot point, asking it where it would point risks a wasted question and death in this scenario.  

There could be something to the additional random robot answer snag.  It is possible that answers from that machine are only random to the observer but the machine can track and even predict them.  The random robot could be 'thinking', "If asked the question I would truthfully indicate the safe door, but for this answer I will be lying."

Actually that very random answer snag is clearly the reason for the 'degree of truthfulness' element in the previous, all but officially accepted answer.  

""What would you do" to a random robot is not a pure logical statement. "

Why?

because it involves a variable, something that is not set either way. Therefore this statement has neither a purely true nor a purely false answer.



"The randomizer may either lie or tell the truth about this one question, but either way
he is behaving like either the truthteller or the liar and thus must correctly report the road to freedom."
This is just false, and I hate having this same point trying to be thrust on us over and over. As pedalhead put it: "Restating my earlier point, the robot isn't random if one can count on it lie or tell the truth consistently; even if only twice in a row."

Pointing is irrelvant. You could change a question like
"If I were to ask you which door leads to freedom, which door would you point to?"  to
"If I were to ask you if this door leads to freedom, would you say yes?" Why would you even mention pointing if the robot couldn't point? Just doesn't make sense.

Anyways, couldn't the random robot just pick an answer to the question without even considering the question? Say half of the time it answers "YES", half of the time it answers "NO". Or even, always answers "YES" regardless of question. Then if you asked it whether 2+2 = 4 it would tell the truth, but if you asked whether 1+1 = 4 it would lie.

Randomly lieing or telling the truth is different from randomly answering "yes" or "no"
A robot who randomly answers "yes" or "no" can answer "no" to
"Will your answer to this question be the truth?"
A robot who randomly lies or tells the truth cannot.

Interesting to wonder if the random answer robot would not simply fling out any answer without evaluating the question.  Since the truth or falseness of the answers are cited as random, vice, say, alternating, to a yes/no question it could simply 'spin an internal yes/no wheel' to respond.  It is true that randomly lying or telling the truth is different than randomly answering, but it could be much like a processor not bothering to evaluate the latter expression in (a zero value operation) && (anything else).  It could be that the random answer robot is not listening because its audio sensor is inoperative but answers anyway because it does not want to be deactivated.  As long as the answer can be defined as truth or lie, it does not violate the riddle constraints.

If it does that the there is no possible answer.

or should i say question?

It is a stretch, and the actual phrasing "one robot might lie, or might tell the truth" marginally implies that it considers the question.  A bit of leverage for the hero is that if the robot that answers starts to ramble about how to define 'is', he will know that one is the full-time liar.

im done discussing.

Forget the robots, spaceman Sid opens each door and has a peek, then chooses the door to Freedom!

Lets not lose focus.

Remember now what I was saying about fiery death behind the door, it may not be obvious at first look... And that is not the point of this riddle. -> the point is to come up with a question that would get Spaceman Sid (SS) past. Any physical possibilities in this question are irrelevant. Like telling one of the robots to go into one of the doors to check it out for you. Or "How long can the question be? - What if it requires the robots two hours to complete the answer... Would that give SS enough time to find a different way out?" - All irrelevant to the concept of the question. As for the orientation of the robots and there perception of a door, again, not the point of the riddle.

I agree with the concept of the lie/truth teller telling either lies or truths (evaluating the question), instead of random answers, or this would be a trick question and not a riddle.

"If you are a liar, which door is the safest?"

Truthful robot will not respond,
Liar robot will point to the bad door
random robot will only repond if it is lying, and will respond with a lie.

or is this a trick question?  "a random robot will answer"  Does this mean literally that a random robot will answer and therefore robot 3 always answers and the other 2 are always quiet?

:-)) Cute - reduce the size of the problem (although I suspect the random robot will have a problem)

Actually, after looking at the question again i realized the original date was 5 months ago and the author never posted again.  I found a very similar riddle online except that you had 3 questions you could ask.  gedmac probably has no idea what the answer is and whoever asked him this riddle originally probably asked it incorrectly and therefor no answer is correct.

The riddle is asked similaly enough to this to be considered to have the same answer.
http://web.archive.org/web/20040821074605/http://rec-puzzles.org/new/sol.pl/logic/smullyan/fork.three.men

jet46: I think there is an answer. But I don't think you can make a robot say nothing. Gedmac hasn't mentioned it but it sounds kinda wierd.

"A robot who randomly answers "yes" or "no" can answer "no" to
"Will your answer to this question be the truth?""

Ah, ozo is quite right. If you substitute 'what would you say if,' or other similar statements with 'the answer to this question' you can force a truth or lie. That way there is no time disparity.

How about something like, "is the answer to this question and the statement that door 1 leads to freedom either both true or both false? "
If Door 1 leads to freedom:
Truth: Yes
Liar: cannot answer
Random: Can only answer yes.

If door 1 leads to FIREY DEATH!:
Truth: No
Liar: cannot answer
Random: can only answer no.

So in preventing an answer that will be a lie with the way we've phrased our question, we can find the safe door. Hooray!

How can u phrase that Random robot will answer yes for the first condition and no for the second one?

How do you think that it has the capacity to answer as both the truthful and the lying one?

Well I guess it depends on how you interpret this statement:
"And one robot might lie, or might tell the truth"
Does this imply this robot always either tells the truth or lies, or can they answer in a way that is neither truth nor lie?

This solution only works if you assume the former.

Question:Is the answer to this question and the statement that door 1 leads to freedom either both true or both false? "
Scenario 1: Door 1 leads to freedom and random answer robot answers no.
Door 1 does lead to freedom.
Now is this answer truth or a lie?
if truth, well door 1 obviously leads to freedom, so that is true, but answer to the statement was no, which is a lie,since this is the truth. But then The answer to that question and the statement that door 1 leads to freedom was neither both true nor both false, which means the original answer was also the truth... which leads into a paradox. So the answer can be neither true nor false.

Similar logic can be applied if the random answer robot answered yes, and the door to freedom was actually the other door.

yet, what is a lie? Can a robot be unresponsive (or any liar). If liar's intent is to deceive asker, then there can become a lot of second guessing between asker and answerer. Supposedly, one can get robotic device into a form of logic loop to inhibit response. Ozo answers are usually found acceptable. I'd disagree, but am unable to link up (among reasons I do not mind pasties as much as links, which are better used to give credit to sources)

Ok its now two weeks since since the last post on this thread, (about the time it took me to wade through all the comments)

But the big question now must be:

How about the soludion gedmac??

Rob.

This is simple math about negatives and positives. My question would be as follows:

If I had asked you yesterday which is the safe door which door would you say?

Regards,
Mike

If I need to explain my question here goes:

Robot 1 Does not lie. Well he will always tell you which is the safe door.
Robot 2 the lier. If I had asked him yesterday, he would lie about it. Today, he also needs to lie about his answer from yesterday, so he would tell me the truth.
Robot 3 sometimes lie. Well he would fall in eirther the same paths of either robot 1 orrobot 2, so he would tell you which is the safe door too.

Regards,
Mike

To gedmac: Can we get some comments from you? Thanks.

mike, what happens when Robot 3 says to himself, well yesterday I would say door (flip coin = heads) 1 is safe. But I have to (flip coin = tails) lie about that now, so I will say that yesterday I would have said door two.

You're asking the robot to make answer two statements in his head. No one said that once he decides to tell the truth for one statement, that every following one must be true.If he arbitratily decides to answer one truthfully and one falsely, then you are every bit as doomed, although your chances for success are as this.

100% 2 of the robots are telling the truth
50% one robot is telling the truth.
=
Overall 83.3% chance of seeing the light of day again.

Not bad odds

Ok let start over to see if you understand my answer. I still stand by asking the following question:

IF I HAD ASKED YOU YESTERDAY WHICH IS THE SAFE DOOR WHICH DOOR WOULD YOU SAY?

Lets say the that Door 1 leads to freedom and Door 2 leads to death, and lets visit each possibility by robot:

1. Robot 1 ALWAYS LIES
Yesterday this robot would lie to you in the first place. Hence this robot would say "Take Door 2".
Now today he lie to you what he told you yesterday. Hence he will tell you "Take Door 1".
Bingo. You know you need to take Door 1.

2. Robot 2 ALWAYS TELLS THE TRUTH
This robot will tell you "Take Door 1"
Bingo, you know you need to take Door 1.

3. Robot 3 SOMETIMES LIES
IF this robot WILL LIE then the following will occur.
Yesterday he will lie, similar to Robot 1, hence today he will also lie about what he would answer to you yesterday, so he will tell you "Take Door 1"
IF this robot decies to tell you the truth, he will tell you "Take Door 1."
Bingo again, you need to take Door 1.

The only part of all my explanation which you might question is the first IF for robot 3. This robot will either lie to you or tell the truth. However, it does not mean that he will give you an answer wher 1/2 is the truth and the other 1/2 is a lie. He will either lie to 1 question or tell the truth in the same question. Regardless whether he decides to tell the truth or lie in any one question, you will get the truth with my question.

I have a concert. How come the auther, gedmac,  of this question has never placed any comments. Does anybody know?

I say a split between bk_jreinstein and Sid The Kid

Problem with the Robot 3 concept is that possibly the veracity of answers alternate with days of the week (the riddle does not specify).  That thing could truthfully answer that he would have lied the day before.

That's the point I was trying to make. Well put aramis

That is why you eliminate the time gap!!! Make the state of the robot the same as when he answers: You don't want to know if it told the truth yesterday, if it'll tell the answer tommorrow, or even tell the truth 2 seconds ago; you want the truth of the answer NOW, the answer to THIS question. Just add "the answer to this question"  to the question and you have solved that discrepancy.

The solution: Is the answer to this question and the statement that door 1 leads to freedom either both true or both false?

I invite anyone else to explain why this works in different words.

As for Sunbow's response to my previous response: So we expect the lying robot to lie. So should the lying robot deceive us by telling the truth, since we think he's going to lie?? Let's not get ridiculous, though we already have gone far beyond that point.

The solution: Is the answer to this question and the statement that door 1 leads to freedom either both true or both false?

This doesn't work.

Try asking the truth robot:

Say door 1 doesn't lead to freedom. Robot1 knows that the answer to does door 1 lead to freedom is false, but he knows that is a true answer, and so he will crash because the answers are neither both true nor both false.

Then truth robot answers "NO"

aah okay I see. I think you're on to something there.

>I say a split between bk_jreinstein and Sid The Kid
Thanks for the praise alainbryden..

I'm totally confused now....

Is my revised answer a possiblr 1st correct answer or not??

considering the author hasn't made one comment since he posted this, I don't think much is going to happen until  amod comes and cleans this up.

You're right about that of course but don't forget to mention that line again when a mod asks for suggestions to split points.
;p

jus kiddin

>>  considering the author hasn't made one comment since he posted this, I don't think much is going to happen until  amod comes and cleans this up.

Maybe a robot should do it.  [Perhaps one named Amod?]

Does anone know why gedmac hasn't answered??.
I thought you deserved some points too aramis11.

>>  considering the author hasn't made one comment since he posted this, I don't think much is going to happen until  a mod comes and cleans this up. Meaning we have to leve this interesting puzzle alone for 21 days?? I don't think that is going to happen.

I had a great idea. I was going to remind gegmacto respond to this question by posting to one of his more "hot" questions. This is what I found: http://www.experts-exchange.com/M_3615063.html

Yeppers, it seems that gedmac is one of those joke accounts - made to ask just one question and then abaondon it to see how long it takes to get deleted. I bet he has a main account that he uses. I suggest that the question be closed down.

Either that, or he forgot his password.

Excellent work Sid_The_Kid.
But did you post a question in comm support???

>>Yeppers, it seems that gedmac is one of those joke accounts - made to ask just one question and then abaondon it to see how long it takes to get deleted. I bet he has a main account that he uses.

Do people really do that??
Then 1 person can create multiple accounts, keep asking questions and answering them from 1 particular account which eventually gets many many points...

That's really bad.

I did not want to post in community support unless we all agree that is the thing to do. I guess that after the authorities post we will have time to discuss what should be done then.

Then I will ask for the question to be closed.

bk_jreinstein, my neighbor came to my house and created multiple accounts (because he kept forgetting the password or something) and he got caught by IP or MAC address (I think). Anyway, I was very lucky my account was not accused of being one of one of his. So it just goes to show that it doesn't pay to cheat.

Thanks BK J.  This is a long string but could have been classified as abandoned a long time back.  It will waste a large volume of text (and points) if it is deleted.  It often appears that P & R frequenters are under-appreciated by the Amod robots.  This scenario could have life-saving implications for space travelers someday.

okay...
yeah as Aramis11 points out a huge no of points and text will be wasted.
Our brains would have worked for nothing :)

http://www.experts-exchange.com/Community_Support/Q_21906267.html

Looks like he cancelled his account.

what??
Then whats gonna happen now??

This is a darn shame. It took a lot of time and energy to come up with an answer we'll never know unless the inventor of the riddle ever knows about this threads medium. I'm sure several of us think we're close to the answer. It was an interesting one and it would be good to know how close we were to the answer. This sounds like we die and never what happens to our souls. :(

Mike

I hope this question is not deleted. I'm reaserching on the net to see if there is other site with someone with the account name "gedmac", that might be the same person we can ask if they placed the riddle in experts-exchange. I have found a few and waiting for a reply.

Looks like this account has only posted 1 question here.

http://www.experts-exchange.com/M_3615063.html

I say as a tribute to our hard work, we continue posting here so that the question remains open FOREVER. I invite you all to my personal MSN space - where there are pleanty of riddles that I made up myself.

I believe I forgot to post the link...

http://cleankidsspace.spaces.msn.com/blog/cns!6545CBDB112D8FFB!106.entry

take the third door hidden around the corner

see, were assuming that there are only two doors near him, and that the door that leads to life is the only way for him to live.

How do we know that the hidden door also does not lead to a fiery death? This could bring up a whole new question: There is one hidden door, and three robots. One robot always lies, one always tells the truth, and one randomly chooses whether to lie or tell the truth. You can ask them one question in order to determine whether the hidden door is trapped or not. If you find that it is trapped, you are doomed... What single question can you ask one of the three robots (you don't know which one is which) in order to get an answer that you can use to determine wheter the door is trapped?

At this rate this topic will never get locked.

>>At this rate this topic will never get locked.
You got that right!

Okay, the question you must ask is "Would you say 'Door 1 leads to freedom'?"


If we assume that door 1 leads to freedom then:

The truth telling robot would say Yes, because he would make that statement.

The lying robot would say Yes, because he would not make that statement, and since a truthful answer of what he would normally say would be No, he must say Yes.

The other robot either tells the truth or tells a lie (he does not simply flip a coin to say yes or no as some of you have said) so if at that given point in time he is telling the truth he would say Yes, if he is telling a lie he would also have to say yes.

If we assume that door 1 leads to a certain death than the robots would have to answer as follows:

The truth telling robot would say No, because he would not lie and say that door 1 would lead to freedom.

The lying robot would say No, because he would lie and say that door 1 would lead to freedom, and since saying Yes would be a truthful answer to the above statement, he must also say No.

Then the robot that either tells the truth or a lie would say No because if at that point in time he is telling the truth he would say No or if at that point in time he is lying he would say No.

So again the answer is "Would you say 'Door 1 leads to freedom'?"

++ = +
-- = +
++ || -- = +

Therefore: I agree.

Are we aware of the fact that this is not the subject of discussion of this question??

You know what? I think this question should be moved...





















to the LOUNGE!!!

So did I win the million dollar prize??  I want the cash option, I don't want the payments over 20 years.

Sid, not too familiar with this site... what is the lounge?

BK... whatcha mean by, "Are we aware of the fact that this is not the subject of discussion of this question??"  I didn't read this whole post... did I miss something halfway through?

I can see that you are really new here so,
Lounge is the place to lounge as the name suggests!
Not really,
it's just a place where people post questions for really low points not really wanting actual answers, just sarcastic ones!

>>BK... whatcha mean by, "Are we aware of the fact that this is not the subject of discussion of this question??"  I didn't read this whole post... did I miss something halfway through?

Yes, you missed something.
We found out that gedmac is a joke account and he/she just asks a question and cancels the membership.
And I also believe that I have given the type of answer that you have give without any assumptions!

Regards,
bk

Warning: do not attempt to post any type of serious question in the lounge. I tried that a while back: http://www.experts-exchange.com/Miscellaneous/Lounge/Q_21778894.html

I'd like to point out that Author hasn't posted since original question.

I'd like to point out that we have already found that out!

Unsubscribing from this one - found it interesting but did only watch it so far,
since it seemed to me that original poster never had a solution for this in mind,
maybe he doesn't like riddles at all and now watching with a malicious grin
how this one goes on in an endless spin, pulling lots of posters into his 'infinite' setup
or maybe like to pull a new record for 'longest discussion thread' ever at EE or
. . . worldwide. Anyway, admire you all for the patience with this one ; ))

I do not expect an answer of any kind. And I am willing to accept that. Especially because the auther no longer has his account.

You should ask Don't  Open the Death door.

 I don't know if anyone else said this yet (so many answers)... but here goes...
  (Designating robots as robot A, B, and C respectively from left to right and asking of robot A)...
  "If I were to ask you if this door was safe, what would you say this robot (pointing to robot B) would say that this robot (pointing to robot C) would say that you would say?"

  It's not foolproof but it does increase your odds from 50/50 to 2/3... 8 out of the 12 possible answers will be lies...

If robot C happened to be the unpredictable one, and you asked another robot "what would robot C say?" Would they even be able to answer the question? After all, THEY don't know what he would say, he's unpredictable, so they wouldn't be able to lie for sure or tell the truth for sure.

I believe my answer on 08/02/2006 02:27PM CDT is a correct answer.  It is a single question and no matter which robot answers it, they will give an answer that can be used to determine which door is which.  

If someone can find a flaw in the question I would love to hear it.

> he forgot his password.
Have him ask the robots what it was

I previously voted to PAQ. I affirm that decision, this form of question repeats and it helps to have references, might as well use it here than of someone else's copy of what is here, even if it is a random 'bot

eric_d_green, the fact that if one interprets the question the way you and many others did, there's ton's and tons of possible correct solutions that involve forcing the three robots to either consecutively tell two lies in a row or two truths, resulting in one possible answer.

What we're exploring now is that if we were to interpret this question as there being a robot that might tell a lie and a truth both in the same question, is there still a question that would produce only one possible answer?

>>is there still a question that would produce only one possible answer?

My question has only 1 possible answer.

you completely failed to realise that your answer only applies to the first interpretation, and both interpretations yeild two very different riddles. Your question suffices for the first riddle. It does not suffice for the second.

What is the second one? When did a second one arise?

alainbryden...
  Interesting point... wouldn't that mean then, if neither the truth-telling nor lying robots could answer due to the uncertainty factor, then the only one that could answer would be the one that is unpredictable...?
  (having just re-read the original question...)  I misremembered that you couldn't specify WHICH robot you were asking the Q of... not as in meaning asking the truthful one but as in Robot A, B, or C...
  That makes it even worse... how do we know that the robot answering is answering for the robot that the question was asked of, assuming you asked the Q of a specific robot...?
  Erf... so the scenarios would play out like this...

1. You enter a hallway terminating with two doors.  There are 3 robots in the hallway just standing around, obviously taking an oil break... You try the doors but find them locked and spur of the moment ask how to get out of here...
2.  You enter a hallway terminating with two doors.  There are 3 robots in the hallway just standing around, obviously taking an oil break... You try the doors but find them locked and notice a sign explaining you have to ask a Q before a door will open.  You say, "What the hell?" and one robot answers...
3.  You enter a hallway terminating with two doors.  There are 3 robots in the hallway just standing around, obviously taking an oil break... You try the doors but find them locked and notice a sign explaining you have to ask a Q before a door will open.  You think of a quick but, barring you being some super genius, clearly flawed question, and get an answer that doesn't do you much good...
4. You enter a hallway terminating with two doors.  There are 3 robots in the hallway just standing around, obviously taking an oil break... You try the doors but find them locked and notice a sign explaining you have to ask a Q before a door will open.  You think long and hard on the proper question, and are killed by your enemies having caught up with you...
5. You enter a hallway terminating with two doors.  There are 3 robots in the hallway just standing around, obviously taking an oil break... You try the doors but find them locked and notice a sign explaining you have to ask a Q before a door will open.  You think long and hard on the proper question, your enemies catch up with you, but upon seeing the predicament you're in, you all agree that whoever runs this place deserves to die a protacted and hideous death and you all go searching for them before continuing with your own problems... =]

Neat concept, if you were to say "What door would the unpredictable robot tell me to take" only the unpredictable robot would be able to answer. Could we spur something off that?

>>if you were to say "What door would the unpredictable robot tell me to take" only the unpredictable robot would be able to answer.

Even if only the unpredictable robot could answer that (which is false beacuse any robot can answer that question), then the question wouldn't work.

This is because it can point to (or direct to in any way) either the firey death door or the freedom door.

I didn't even suggest the question would work, which is precisely why I asked if we could "spur something off that".

In addition to that, I would like for you to tell me how the other two robots would answer that question.

Why can't they?

They couldn't answer the Q for the simple reason that the concept would presumably be that the unpredictable robot won't even know what answer it'll give until it's basically giving it... "truth/lie, truth/lie, hmmm... what to say, what to say..."

What dagesi said. How is a robot that is always supposed to tell the truth tell you something he doesn't know. How about the one that always lies? He can't answer you, because he doesn't know the answer. if he guesses, he might be right, so he can't guess, because he has to lie.

You see that will only lead toa deeper mess and when they answer randomly, if the truth robot get to answer, you won't get any answer.

"You're in a room with 5 dead people and 1 live person and you ask a Q of them and one randomly answers."
It's not exactly your fault that the 5 dead ones are unable to answer and so the "one randomly" means one randomly out of one...
=]
Now it's just a matter of having a Q that will always return the truth (or a lie) when asked of the unpredictable robot...

How can it be random if you are given only one choice????

Let me use a definition which fits...
"being or relating to a set or to an element of a set each of whose elements has equal probability of occurence"  I got this out of a dictionary, word for word...
So even if it might not seem random in the way people INTEND the word, it's still random...
Mathematically, I don't see that "pick a number between one and ten" is any less random than "pick a number between one and one".  Sure, there are more choices, but both are random.

I'd like to point out that there is no number 'between' one and one.

When you say "pick a number between one and ten" your average person MEANS "pick a number between one and ten, inclusively"... otherwise no one could pick one or ten...
So saying "between one and one" should mean "pick a number between one and one, inclusively" which would allow one to be an option...

Technically, between means 'in between' a range 'exclusive' of the beginning and ending of the range.

Why are we arguing over a 'between'??
lol :)

Well, since it's between you and me, my guess would be it has nothing to do with either of us... =P

The average person is too ignorant to understand the definition of 'between'. There could be an infinite number of selections between 1 and 10 by various decimal places, e.g., 4.689, but if one wants to ignorantly assume 'integer' for 'number', the choices between 1 and 10 are: 2 3 4 5 6 7 8 9. Suggestion: When asked to "pick a number between one and ten", it may be revealing to answer "pi".

You were full and, having paid for it, were going to give your two friends a choice of who gets the last slice of pizza.
Unfortunately, in the time it took you to say, "Each of you verbalize the value of an integer whose value is greater than or equal to 1 and less than or equal to 10 and the one who selects or is closest to the same integer value I have currently opted in the same range shall get the remaining slice" your younger brother dashed through and snagged it... dang... =]

So many Notifs on a dead thread, or, the question that wouldn't end. I was about to go nonotif away, but in curiousity and to help anyone stand up to the deleting Mods, here ya go (compare to any Tech TA):
-----------------------------------------

Posting Counts

38      bk_jreinstein
20      Sid_The_Kid
16      Aramis11
14      SunBow
13      alainbryden
10      jkmyoung
9      ozo
8      dagesi
7      mikeayuso
4      rcherne1
3      JakobA
3      pedalhead
3      jet46
3      eric_d_green
2      MizzL
1      H4gg0n
1      phileoca
1      theProfessa
1      GnarOlak
1      foxcon
1      freebuddy
1      rsunga
1      MarkDozier
1      nltech
1      ram_einstein
1      naoy
1      hiteshgupta1
1      RBertora
1      cheeseyhead
1      Geisrud
1      xberry
1      imran_fast

170      Total Postings

Yay! I'm number 1 and this makes it 39!

Wow, I can't believe you sat there and figured all this stuff out. Don't tell anyone to close this question. It will grow and grow. It is the only question of its type that is not in the lounge. Gedmac would be proud. And it is hurting my brain to read all this noob stuff, which is a good thing, in some ways.

Gedmac isn't here to be proud.

">>if you were to say "What door would the unpredictable robot tell me to take" only the unpredictable robot would be able to answer.
Even if only the unpredictable robot could answer that (which is false beacuse any robot can answer that question), then the question wouldn't work.
This is because it can point to (or direct to in any way) either the firey death door or the freedom door."

"And one robot might lie, or might tell the truth"
The trick I suggest is making it so that telling a lie is a paradox.

For example, if you asked the robots:
"Is your answer a lie?"
Truth robot would say no.
Lying robot could say no, but then it would be the truth, but then it would be a lie, etc..
if lying robot said yes, then it would be a lie, but would be the truth, etc...
So lying robot cannot answer without causing a paradox.
Similarly, Unpredictable robot can only answer no. If it answered yes, then it would be a lie which was a truth etc... so was actually neither but a paradoxical question.

Is the answer to this question and the statement that door 1 leads to freedom either both true or both false?

Or you could just take out the whole complex part about the statement and the both true/false

And change the question to "If I asked you which door leads to freedom, which door would you tell me?"

This question is much more simple, has the same effect, and would even work if there were more than 2 doors.

Well actually, if there were more than 2 doors, then the lying robot could pick either door and say he would tell you the opposite door than the one he initially chose. Therefore you would have to change the question to

"If I asked you which door leads to freedom, which door do you think would be a possible response?"

I think that that would just about qualify as a universal answer to any such question involving multiple paths and multiple people answering one question (some lying, some not)...

Do the robots know which door leads where???

obviously!

Sid_The_Kid > Wow, I can't believe you sat there and  

it's a handme down script, not too buggy. once in mood (ex: already logged on) it is closer to seconds to do than a minute. Tailored more perhaps for grading a thread with fewer participants. Looking at the list it seems so comparatively long that a count of total participants would be interesting to me. SOme might want to try on some percentage formaluae, whatever local interest is.

But for me to actually count the lines listed would take loger than using script with a copy then a paste back to EE  of result. So I'd prefer to count the participants by starting eaup excel (f not started) then copy the table lto it, look at the line number and then report the total. That's about how long it took to do table.

So, if not that, then, why all this time on this comment? For a thread that is dead and I have lost interest in? Truth is, I have something to do, but not for a little bit. Ok, truth also is:

 > Wow, I can't believe you sat there and  

yeah, can't believe I did the comment let alone the return to the thread.

> Don't tell anyone to close this question. It will grow

you'll need a <ping>, something like one comment a week or it self destructs

er, has anyone seen the recharge device around anywhere lately? The robot by me is slowing down to a crawl, will be needing a place to plug into by yesterday or its abillity to game will be completely gone

Was that what that was...?  I just thought it was a piece of junk laying around... if you hurry, maybe you can get it back out of the recycle bin before it gets picked up... =]

I think you just need to post every 14 days or so. Since this question will pretty much always be on the front page of the riddles section I doubt it will be deleted any time soon. I am proud to be a part of this ridiculous anomaly, and I'll bet it'll be here 5 years from now until EE changes their rules on deleting questions to account for things like this.

This is crazy! Should I request a PAQ in the comm support?

12/17/2005  
09/29/2006

so we are having a contest of egg first vs sid Robots ............i might thin who wins !! question deleted first will loose :)and he has to answer

egg comes first or hen

OR

Which door to leave !!!

lol

@Sid_The_Kid

would u like to see this question closed :) ................

That should've been @spaceman sid. :)

>>I am spaceman sid's kid   (2nd post)

well spaceman sid is still waiting to open the three doors !! for abt 8 months ....he might have been died fasting or with having no food ....  

here is a point how could spaceman sid remains living for 8 months in space ?

Responses:
"Or you could just take out the whole complex part about the statement and the both true/false"
No, you can't. This adds the time disparity, which is, the unknown robot may say 1 thing one time, and a different thing the next. You must refer to the answer to the current question in order to use this trick. This problem is explained throughout the answers to this question, so I won't repeat it again.

"Therefore you would have to change the question to
"If I asked you which door leads to freedom, which door do you think would be a possible response?""
Possible Responses:
Door 1, Door 2. the lying robot could not answer. The truth telling robot (as well as the random robot) could answer either door.

>>how could spaceman sid remains living for 8 months in space ?
Exactly why he is SPACEMAN SID!!!

>> why he is spaceman sid ?

then by this it is proved that spaceman do not eat something for years and years ....!! hmm sounds interesting , also one more thing spaceman sid was escaping from his enemies .....after 8 months still he is stuck at three doors ...he might be killed by his enemies during asking the robots ....thus the question is not valid now after 8 months since spaceman SID dies may be if not with food then his enemies killed him !!!

MAY HIS SOUL REST IN PEACE !!!

What are you talking about? If Spaceman Sid could kill one of his enemies, two things could happen:
1. He could take the buys clothing and pose as a guard then escape later, OR
2. He could eat the enemies body's for as long as it takes for the answer to find the answer to the conundrum

make sure Spaceman sid is alone and there might be man enemies chasing him ? ..so how long could spaceman sid can fight ??

a that point is valid still that he could eat bodies of his enemies ....well wont there be reinforcements arriving at the doors to help either spaceman sid or  his enemies ??

if this would happen then there would be a mega fight resulting in .... ??

abt the clothing well since there are three doors and each door have a robot on it ....Sid have to destroy  a robot in order to pose as a guard ...hmm then where would the body of robot went ?? Spaceman sid may create a suspicious doubt on  enemy  mind  ??

Okay, now everyones talking crap!

>>>ok, now everyones talking crap

even ur answer in not up to the mark bk  ;) ..............but my points are valid still .............pls give the answers to them ..!!

>>even ur answer in not up to the mark bk  ;)

I didn't say so! Nor am I up to contradicting a good friend or for that matter anyone. :D

Anyway, to add fuel to the fire:

I asked my friend this riddle and he suggested that the answer might involve confusing the robots. I mean, obviously I have already answered the riddle >.> But since we are still here talking I might as well point this in a less retarded direction.

What if you could trick the lying robot into telling the truth? Or obviously giving away the answer. Then there could be an alternative answer to this riddle.

Thinking about this, I realized there really was another logical answer. But where would my sportsmanship be if I told you?

Tell me now! I want to know!

Nope

Why not?

Because that would take all the fun out of this.

I'll give you a hint in six months.

What? Six months???
ok...

Na, I'll give a hint the next time 13 days has gone by and a comment has not been posted, to keep this question active.

so all this ends up ....in Keeping the question active ....good :)  ....................
********************************************************************
I didn't say so! Nor am I up to contradicting a good friend or for that matter anyone. :D


ah ......i was not mean anything wronge dear bk ....just adding some fun ....to harsh feelings :)  ..................

>>ah ......i was not mean anything wronge dear bk ....just adding some fun ....to harsh feelings :)  ..................

Ah, I didn't think you were...

An improvement on the previous solution: With this one, even the lying robot can answer.
Is your truthfulness to this answer equivalent to that of the statement that Door 1 leads to safety?

If Door 1 leads to safety:
Truth robot. Yes.
Lying robot. Yes. (this robot is still lying! = False, however Door 1 leads to safety which is true! so this is a successful lie.)
Random robot. Yes, (for either of the 2 reasons)

Why does the lying robot answer yes? Well Door 1 leads to safety. -> true. She will lie, so the truthfulness of the answer -> false. So it is not equivalent -> no. So the lying robot lies as programmed and says Yes.

If Door 2 leads to safety:
2a. Truth Robot: No.
2b. Lying robot: No.
2c. Random Robot: No. (for either of the 2 reasons)

Let's look at the truthfulness of the statements:
2a. Door 1 Leads to safety? -> False
Truth robot tells the truth? -> True
Are they the same? No.
Truth robot tells the truth and says "No."

2b. Door 1 Leads to safety? -> False
Lying robot tells the truth? -> False
Are they the same? Yes.
Lying robot lies and says "No."

Since random robot either tells the truth or lies, if he tells the truth, follow the logic of 2a. If he lies, follow the logic of 2b.

Final solution:
"Is your truthfulness to this answer equivalent to that of the statement that Door 1 leads to safety?"

God .. I can't believe you all fell for that one.. again

Kidding.. I do believe it.  :|/

Z

nobody explained abt what type of deaths sid might face ?? if he told lie ?? .....and freedom he may face  if he says truth ??? ...........

still sid was not able to escape .....!! .......why dont some one assasinates him forgod sake so that this question may be closed  .......


________________________________
ah ......i was not mean anything wronge dear bk ....just adding some fun ....to harsh feelings :)  ..................

correction =  NO harsh feelings !!

I realised the correction....

This has probably been answered, but there are so many posts here, I don't have time to read them all and, given what many of them have to offer, I'm not sure I would gain anything in doing so.
The question is -
If I asked one of you robots if this door(selecting one of the doors) was the door to the fiery death, would you say yes or no? No matter which robot answers, if it says no go through it, if it says yes, go through the other one.

In a question this long, you are not gaining anything for posting period.

Now, can anyone figure out the alternative answer to the riddle?

Hey, I think thats brilliant! No, it has not already been given.

Hmm, although it all means the same thing, that actually is a great way to ask it. Good work. But my may is 4 000 000 000 times... um... different. Here's a hint: SpacemadSid had to come from somewhere...

well spaceman sid comes from where ???  .......hmm from pluto .. ??? or from jupiter's so many moon ....or a far wide galaxy ?? ......well he should be on a ship or a super bike which fly ...because only these thing can save sid from his enemies .....  

It's a fairly general answer (ie it can apply to this riddle if it were asked in a different setting with different characters).

He came from outside after opening a door so he has to be able to go back out of hte room the same way. Right?

Nope, my answer is an actual working solution. A real question.

Reviewing previous solutions:
Jet46: "If you are a liar, which door is the safest?"
A liar is someone who has told a lie, so the random robot could consider herself a liar. She could decide to tell the truth this time, and answer the safe door.
-- So change the sentence to "If you are lying, which door is the safest?"
The truth teller could answer either door. Why? Because a false proposition implies any statement.
Since they are not a liar, they can answer whatever they want. If they were a liar, that door would be the safest; however, they will never be a liar.



Eric_d_green: "Would you say 'Door 1 leads to freedom'?"
Random robot,
If door 1 led to freedom, then the robot could at some time tell the truth and say "Door 1 leads to freedom."
If door 2 led to freedom, then the robot could at some time tell a lie and say "Door 1 leads to freedom."
So the answer to this is "yes" for the random robot.

The random robot could then tell the truth and say "yes".
The random robot could then tell a lie and say "no".

No information gained.



H4ggon "If I were to ask you whether the left door leads to freedom, and you chose to answer that question with the same degree of truth as you answer this question, would you then answer 'yes'?"
Lol, this is the near correct answer all along in the 2nd post, but the author himself discounts it because of a misinterpretation between 'random' and "might lie, or might tell the truth."
No one really chose to tackle this one because of the author discounting himself, and the statement he asks is quite complicated. A gentle rephrasing is need to change it into the present tense. Shortened to "Is the truthfulness of 'Door 1 leads to safety' equivalent to the truthfulness of the answer to this question"

I think H4ggon should get 80% of the points to this question.

The good thing abt it is that therer would be no one to split the answers  ;)  ........thats cool !! ........why do even sid the space man thinked of getting out to fight with his enemies ?? :P ......its just the winter season he have to sleep in the bed ... ...!!

Happy anniversary.
This question has been open for so long that link to the original answer given in http:#a15505474 has long since expired
But it is can still be found archived at
http://web.archive.org/web/20040821074605/http://rec-puzzles.org/new/sol.pl/logic/smullyan/fork.three.men

lol

hahha nice ozo !!

Merry Christmas.

Merry Christmas!

Merry christmas !!

ah what else left here ......greetings , religion , hens , eggs , sid , enemies , spaceships ,fights , escapes

i think love affairs are only left in this thread !! ........i love u BK :- )  lets start with this

:-)

hey bk .....can this thread be closed ?? .....what would happen if this becomes closed :(

I already asked if it could be closed in community support and I was told that it couldn't because of the way EE works. The owner of the question has to be the one to ask for it to be closed. Or we could wait for cleanup to take care of it (after 14 days on no postings).

there were over 14 days on no postings between http:#a16043591 and http:#a16190289,
between http:#a17093838 and http:#a17200145,
and between http:#a17965564 and http:#a18158210
http:#a16694427 to http:#a16813394 missed it by a few hours
The criterion for review should probably be more like 14 days of no postings or
7 days of no postings with 28 days of no postings by the author

I think after two weeks of no postings someone has to complain about it to support. But who would want this question to be closed down anyway?

Why? Don't you want this question to be closed?

No way this question is the best! [tear] you guys are like family to me. And also, I have a bet that this question will last for at least three years.

lolzzzzzzzzzzzzzzz............... It's going to be a looooong year
;)

It's impossible!

where the F^<? has that..Do Not Send Me Any More emails From This Question... button gone!

lol didn't it used to be in the email they sent?

http:/questionNotify.jsp?qid=21668168&subscribe=0

sid it did
ok ozo..now it's personal..\/

300/200 me / bk_jreinstein

Though much effort seems to have been expended, I don't recall actually seeing any answer that was without a problem... ergo, no successful answer.
There were many instances of people SAYing they had a viable answer but A) the logic has seemed faulty, B) the "question" not really a question, C) multiple questions being asked,  or D) assuming evidence not defined in the original question.
I've really no pref either way though...

Mine was successful

It would be funny if administrator AnnieMod forgot to close this question.

>bk_jreinstein...
Just curious, but which answer of yours are you referring to...? (not saying multiple answers aren't ok, just want to be sure what to respond to...)

All the correct answers are logically equivalent to the answer that was at the link in the very first reply.

Yea, but no one actually read that.

H4gg0n seems to have read it

oh my god ....this legendary question is abt to close ...... :(

I invite u all in the funeral of this question ....kindly bring some gifts for the organizers (i.e me) ........i also feel sad at the death of the sid ...his enemies cought him and burned him alive in concentrated sulphuric acid !! ...........if people here would be serious sid's life could be saved :(




____________________
     Rest In peace !!
                         

AnnieMod, you had fun reading this I presume??
Thanks anyway... ;)