Question

Given two independent events A and B such that P(A) = 0.3 and P(B) = 0.6, find P(A’ ∩ B’).

Answer 1

P(A’ ∩ B’) = P(A ∪ B)’

= 1 – P(A ∪ B)

= 1 – 0.72

= 0.28

Another Method:

P(A’ ∩ B’) = P(A’).P(B’)

= [1 – P(A)] [1 – P(B)]

= [1 – 0.3] [1 – 0.6]

= (0.7).(0.4)

⇒ P(A’ ∩ B’) = 0.28