The probability mass function of X is given by (r+k p(k) = (+-)p(1 - p)* k = 0, 1, ... Give a possible intepretation of the random variable X. Hint: See Exercise 23.

In Exercises 25 and 26, suppose that two teams are playing a series of games, each of which is independently won by team A with probability p and by team B with probability 1 - p. The winner of the series is the first team to win i games.