Answer parts a and b.

Question

1. find n(a)

a. n( a ∪ b ) = 20

n( a ∩b ) = 18

n (b) = 20

2.if n(a)=20

n(b)=7

n(a ∩ b) = 5

Answer 1

1) Venn Diagram says 20 in B and 18 in the intersection. So 2 are in B only.

That leaves zer0 for A only.

2) Venn Diagram says 20 in A and 5 in the intersection. So 15 are in A only.

Also 7 - 5 = 2 in B only