A chess game between two grandmasters X and Y is won by whoever first wins a total of two games. X's chances of winning, drawing or loosing any particular game are a, b and respectively. The games are independent and a + b + c = 1 49. The probability that X wins the match after (n + 1) th game (n 1), is (a) na fn-1 (c) na bc-1 50. The probability that Y wins the match after the 4th game, is (a) abc (2a + 3b) (b) bc(a + 3b) (c) 2ac(b + c) (d) 3bc(2a + b) (b) na b(b + (n 1)c) (d) na b"- (b + nc) 51. The probability that X wins the match, is a 3 a(a + 2c) (a) (a + c) a(a + 3c) (a + c) (b) (a + c) (c) (d) 3 (a + c)