11. (a)An urn contains 8 red and 12 white balls, identical except for colour. An experiment consists of drawing one ball at random from the urn. Let X=1 if a red ball is drawn, and let X=0 if a white ball is drawn. Give the probability mass function, mean and standard deviation of the random variable X. (b) Suppose that in A11 (a), X=1 if a red ball is drawn, and let X=1 if a white ball is drawn. Give the probability mass function, mean and standard deviation of the random variable X