Question

Given that S = 50, A = 30, and A ∩ B = 1, find A′ U B′.

Answer 1

The size of a set is called the cardinality, and is represented by |A| for the cardinality of A.

Do you mean:
Given that |S| = 50, |A| = 30, and |A ∩ B| = 1, find |A′ U B′|.
?

Answer 2

yup :)

Answer 3

Sorry to say, but math (especially symbols) has to be very precise.

Answer 4

mathmate is right it makes a bug difference with the symbols

Answer 5

hint:

Can you figure out \(|B - (A\cap B)|\) and hence \(|A'\cup B'|\)

Answer 6

no sorry :(

Answer 7

Have you done Venn diagrams before?

Answer 8

yup but not like this

Answer 9

sorry :(

Answer 10

no problem.
I suggest you watch this video before continuing:

https://www.youtube.com/watch?v=ST2LBM5dmeE
or following the reasoning of this:
http://sites.csn.edu/istewart/mathweb/Math120/SetTheory/survey.html

Answer 11

thank you :)