(7) Suppose that A and B are mutually exclusive events for which P( A) = 0.5, P(B) = 0.3. What is the probability that (a) either A or B occurs; (b) A occurs but B does not; (c) both A and B occur? (8) Suppose that A and B are independent events for which P(A) = 0.5, P(B) = 0.3. What is the probability that (a) either A or B occurs; (b) A occurs but B does not; (c) both A and B occur? (9) Suppose that A, B and C are independent events for which P(A) = 0.5, P(B) = 0.3, and P(C) = 0.1. Find the probability (a) that at least one of the three events occurs. (b) exactly one of the three events occurs. (10) An urn contains 3 red and 7 black balls. (a) You randonly draw the balls out one by one without replacement. What is the probability that the last red ball was the 8th ball out? (b) Player A and B withdraw balls from the urn consecutively until the first red ball is selected. Find the probability that A selects the first red ball. ( A draws the first ball, then B, ans so on. There is no replacement of the balls drawn.)