If A and B are events such that P(A|B) = P(B|A), then
(A) A ⊂ B but A ≠ B
(B) A = B
(C) A ∩ B = φ
(D) P(A) = P(B)
13 3  Multiplication Theorem on Probability
Let E and F be two events associated with a sample space S Clearly, the set E ∩ F
denotes the event that both E and F have occurred In other words, E ∩ F denotes the
simultaneous occurrence of the events E and F