WAEC Further Mathematics 2024 Theory question 105

Theory question 105

Probability

Two events M and N are such that P(M) = 1/2, P(N) = 9/20 and P(M ∩ N) = 11/50. Find: (a) P(M ∩ N′); (b) P(M′ ∩ N).

Show the model answer

Model answer

(a) P(M ∩ N′) = P(M) − P(M ∩ N) = 1/2 − 11/50 = 14/50 = 7/25.
(b) P(M′ ∩ N) = P(N) − P(M ∩ N) = 9/20 − 11/50 = 23/100.

Explanation

A Venn diagram shows 'M only' and 'N only' clearly.