3 Let A and B b two events defined on a sample space S such

(3) Let A and B b two events defined on a sample space S such that P(A) = 0.3, P(B) = 0.5 and P(A B) = 0.7. Find (a)P(A\' B\') (b) P (A B\')

Solution

P(AUB) = 0.7

i.e. P(A)+P(B)-P(AB) = 0.7

Hence P(AB) = 0.3+0.5-0.7 = 0.1

----------------------------------

(a) P(A\'UB\') = 1-P(AB) = 1-0.1 = 0.9

---------------------------------------

b) P(A int B\') = P(B) - P(AB) = 0.5-0.1 =0.4