Question

Let A and B be two events such that the probability that exactly one of them occurs is 2/5 and the probability that A or B occurs is 1/2. then the probability of both of them occur together is

(1) 0.02

(2) 0.01

(3) 0.20

(4) 0.10

Answer 1

Answer is (4) 0.10

Answer 2

Answer is (4) 0.10

P(A) + P(B) - 2P(A ∩ B) = 2/5

P(A) + P(B) - P(A ∩ B) = 1/2

P(A ∩ B) = 1/10