Question

if n(U)=38, n(A)=16, n(A∩B)=12, n(B')=20, find n(AUB)

Answer 1

n(b)=n(u)-n(b')
n(b)=38-20
n(b)=18
n(aUb)=n(a)+n(b)-(A∩B)
n(AUB)=16+18-12
n(AUB)=22