Question

URGENT!!!

SIMPLIFY :

(A intersection B) union (A - B).

2 ) FOR ANY TWO SETS prove that P(A) intersection P(B) = P(A n B).

3 ) let A , B , C be three sets such that A u B = C and A n B = phi . Then prove that A = C - B.

Answer 1

Let the number of elements in set A be n(A) and in B be n(B).

Now through Venn diagrams we can easily say that

n(AUB)= n(A)+n(B)-n(A intersection B)

As A and B are disjoint sets n(A intersection B) = 0

This implies, n(AUB)=n(A)+n(B)