Let P(E) denote the probability of the occurrence of event E. If P(A) = 0.5 and P(B) = 1 then the values of P(A | B) and P(B | A) respectively are
- A. 0.5, 0.25
- B. 0.25, 0.5
- C. 0.5, 1
- D. 1, 0.5
Answer: C. 0.5, 1
Explanation: P(B)=1 means B is certain. P(A|B) = P(A n B)/P(B). If B is certain, A n B = A? Yes. So P(A|B) = P(A)/1 = 0.5. P(B|A) = P(B n A)/P(A) = P(A)/P(A) = 1.