Solved

Need help in equation

Posted on 2011-09-06
8
320 Views
Last Modified: 2012-05-12
Hi guys: Can any one please help me in that question ? Thanks.

How many integers in the set {n belongs to Z | 1 less than equals to n less than equals to 700} are divisible to 2 or 7 ?

0
Comment
Question by:mustish1
  • 3
  • 3
  • 2
8 Comments
 
LVL 37

Expert Comment

by:TommySzalapski
Comment Utility
Well, since this question has an academic nature to it...
How many are divisible by 2 (easy)
How many are divisible by 7 (also easy)
How many are divisible by both (not too hard)

Once you have those, the answer should be pretty easy to come up with (please no one jump in with just the answer).
0
 
LVL 8

Accepted Solution

by:
stalhw earned 300 total points
Comment Utility
1 less than equals to n less than equal to 700
that doesn't make sense...
you probably meant
1 <= n <= 700
So the set is integers from 1 to 700 ?
then it shouldn't be too hard...

one in seven will be divisible by 7... so 100
one in 2 is divisible by 2... so 350
0
 
LVL 37

Assisted Solution

by:TommySzalapski
TommySzalapski earned 200 total points
Comment Utility
Remember from set theory A or B = A + B - (A and B)
0
 

Author Comment

by:mustish1
Comment Utility
1 <= n <= 700
divisible to 2 and 7

k. just divide 700/2 and divide 700/7

its easy thanks.
0
Top 6 Sources for Identifying Threat Actor TTPs

Understanding your enemy is essential. These six sources will help you identify the most popular threat actor tactics, techniques, and procedures (TTPs).

 
LVL 37

Expert Comment

by:TommySzalapski
Comment Utility
Yes, but the answer is not 350 + 100 = 450 because if you do that, you'll count some twice. (i.e. 14 is divisible by both and is counted twice).
0
 
LVL 8

Expert Comment

by:stalhw
Comment Utility
oh he meant disisible by both?
well half of the divisible by 7 will also be divisible by 2....
(7,14,21,28,35,42,etc easy to see that half are pair)

so 50 will be divisible by both
0
 
LVL 8

Expert Comment

by:stalhw
Comment Utility
and if you want divisible by 2 OR 7,
just remove the 50 that are divisible by both... so 350+100-50 = 400
0
 

Author Comment

by:mustish1
Comment Utility
ok thanks
0

Featured Post

Highfive + Dolby Voice = No More Audio Complaints!

Poor audio quality is one of the top reasons people don’t use video conferencing. Get the crispest, clearest audio powered by Dolby Voice in every meeting. Highfive and Dolby Voice deliver the best video conferencing and audio experience for every meeting and every room.

Join & Write a Comment

Suggested Solutions

Title # Comments Views Activity
Table function 6 41
Homework Math Question 1 57
Separation of duties 5 40
Car Question: Honda CRV 2005 Knock Sensor 4 33
Article by: Nicole
This is a research brief on the potential colonization of humans on Mars.
EE introduced a new rating method known as Level, which displays in your avatar as LVL. The new Level is a numeric ranking that is based on your Points. This article discusses the rationale behind the new method and provides the mathematical formula…
Articles on a wide range of technology and professional topics are available on Experts Exchange. These resources are written by members, for members, and can be written about any topic you feel passionate about. Learn how to best write an article t…
Where to go on the main page to find the job listings. How to apply to a job that you are interested in from the list that is featured on our Careers page.

728 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now