Solved

Math homework question

Posted on 2016-10-06
5
107 Views
Last Modified: 2016-10-06
My teacher shows this in the class but I dont understand it. Is it ok if experts can explain this question? I donot understand how it calculate the B'? According to my calculation B'={2,4,6,8,12,14,16,18,22,24,26,28,32,34,36,38,42,44,46,48,52,54,56,58,62,64,66,68,72,74,76,78,82,84,86,88,92,94,96,98} but in the book it solves B'=6

screenshot.PNG
0
Comment
Question by:Tommy Anderson
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
5 Comments
 
LVL 26

Assisted Solution

by:Shaun Kline
Shaun Kline earned 250 total points
ID: 41831869
If I understand the notation being used, B' is the complement of B. So you are correct in that B' is all of the positive integers not divisible by 5 up to and including 100.

However, the solution is using a shorthand approach to solve n ( A intersect B' ) by understanding that this is asking for the number of elements in A that are not in B.

Since you already determined that there are 6 elements in both A and B, then the number of elements that are just in A is 33 - 6.
0
 
LVL 34

Expert Comment

by:ste5an
ID: 41831890
How are A' and B' defined?
0
 
LVL 27

Accepted Solution

by:
d-glitch earned 250 total points
ID: 41831901
I am afraid you are missing quite a lot:

A = { 3, 6, 9, ... , 99)    
A' = { 1, 2, 4, 5, 7, ... 100}  <== everything that is not in A

B =  {5, 10, 15, ... 100}
B' = { 1, 2, 3, 4, 6, 7, ... 99}  <== everything that is not in B

n( B) = 20  <== The number of elements in B not the elements themselves.
n( B') = 80  ==>  The number of elements in U minus the number of elements in B

Your answer   B' = { 2, 4, 6, 8, 12, ... , 98}  does not make sense for this problem.
There is now mention of even (or odd) numbers.
0
 

Author Comment

by:Tommy Anderson
ID: 41832215
Thanks guys and d-glitch. I just want to ask one more thing, is it OK to post book examples with page numbers if I am not be able to understand it or my teacher work if there is something in the steps I need help?
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: Nadia
Suppose you use Uber application as a rider and you request a ride to go from one place to another. Your driver just arrived at the parking lot of your place. The only thing you know about the ride is the license plate number. How do you find your U…
Lithium-ion batteries area cornerstone of today's portable electronic devices, and even though they are relied upon heavily, their chemistry and origin are not of common knowledge. This article is about a device on which every smartphone, laptop, an…
This is a video describing the growing solar energy use in Utah. This is a topic that greatly interests me and so I decided to produce a video about it.
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…

696 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