Question

If P (A) = 0.8, P (B) = 0.5 and P (B|A) = 0.4, what is the value of P (A ∩ B)?

Answer 1

Answer : 0.32

Explanation :

Given :

P (A) = 0.8, P (B) = 0.5 and

P (B|A) = 0.4

Step 1 :

By using conditional probability, we get

P (B|A) = P(A ∩ B)/P(A)

P (A ∩ B) = P(B|A). P(A)

Step 2 :

P (A ∩ B) = P(B|A). P(A)           

                 = 0.4 x 0.8

                 = 0.32

Thus, P (A ∩ B) = 0.32

0.32