Solved

Math homework question

Posted on 2016-10-06
5
103 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

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

How to Win a Jar of Candy Corn: A Scientific Approach! I love mathematics. If you love mathematics also, you may enjoy this tip on how to use math to win your own jar of candy corn and to impress your friends. As I said, I love math, but I gu…
Article by: Nicole
This is a research brief on the potential colonization of humans on Mars.
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…

734 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