題組內容

Let P(Ai) be the probability that the car is behind door no, i. Thus, the probability that the car is behind door no. I is P(A1). Let P(B) be the probability that the contestant picks door no. j, and let P(Ck) be the probability that the host picks door no. k. Note that P(C3lA2, B1) is the probability that the host opens door no. 3 after the contestant picked door no. 1, and the car is behind door no. 2.

(vi) State the probability P(C3|A1， B1) (2 pt.)