1. A bin contains some green, some red and some blue balls. Two balls are drawn from the bin. Let X be the number of red balls drawn. Find the probability distribution function and the cumulative distribution function of X in each of the following situations. (a) There are 6 green, 5 red and 4 blue balls in the bin, and the first ball is set aside before the second draw is made. (b) There are 4 balls of each colour in the bin, and the first ball is put back in the bin before the second draw is made. (c) There is only one ball of each colour in the bin and the first ball is held in the hand of the person making the draws while the second draw is made.