Evaluate P(A ∪ B), if 2P(A) = P(B) = 5/13 and P(A|B) = 2/5.

Given: and

……….(i)

We know that

By definition of conditional probability,

⇒ P(A ∩ B) = P(A|B) P(B)

……….(ii)

Now, ∵ P(A * B) = P(A) + P(B) – P(A ∩ B)