Question

If n(A)=7. n (B)=13, and nA n B)=4, then find n (A u B ).solve

Answer 1

Answer:

16

How did I get this answer first of all?

Formula for finding the answer is,

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

Hence,

n(AUB)=7+13-4

= 20-4

=16