Question

Let n(A) 30, n(B) = 27 and n(A∪B) = 45, find: n(A - B).

Answer 1

n(A) = 30, n(B) = 27 and n(A ∪ B) = 45

We know that,

n(A-B) = n(A ∪B) – n(B)

n(A – B) = 45 – 27 = 18