Question

For two events A and B in the sample space of a random experiment , P(A) = 0.6,P(B) = 0.5 and P(AՈB) = 0.15, Find (1) P(B-A) (2) P(A’Ո B’) (3) P(A’UB’)​

Answer 1

p(A) = 0.6, p(A') = 1-0.6 =0.4

p(B) = 0.5, p(B') = 1-0.5 = 0.5

1) p(B-A) = p(B n A') =p(B)×p(A') = 0.5×0.4 =0.2

2)p(A' n B') = p(A')×p(B') = 0.5×0.4 = 0.2

3)p(A' U B') = p(A') + p(B') -p(A'nB')

= 0.4+0.5 - 0.2

=0.7