Question

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

Answer 1

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

We know that,

n(B – A) = n(B) – n(A n B)

n(B – A) = 20 – 6 = 14