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Question
A and B are two events such that P (A) ≠ 0. Find P (B|A), if A ∩ B = Φ.
Solution
P(B|A) = `(P(B ∩ A))/(P(A)) = (P(A))/(P(A)) = 1`
A ∩ B = Φ i.e, P(A ∩ B) = P(Φ) = 0
⇒ P(B ∩ A) =`(P(B ∩ A))/(P(A)) = 0/(P(A)) = 0`
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