Question

The probability that atleast one of A and B occur is 0.6. If A and B occur simultaneously with probability 0.2, then find P(\(\bar{A}\)) + P(\(\bar{B}\)).

Answer 1

Here P (A ∪ B) = 0.6, P (A ∩ B) = 0.2

P (A ∪ B) = P (A) + P (B) – P (A ∩ B)

0.6 = P (A) + P (B) – 0.2

P(A) + P(B) = 0.8

P(\(\bar{A}\)) + P(\(\bar{B}\)) = 1 – P(A) + 1 – P(B)

= 2 – [P(A) + P(B)]

= 2 – 0.8

= 1.2