A game consists of flipping a coin repeatedly until two heads or two tails are obtained. Assume that flips are independent and that at each flip P(H) = 0.6 and P(T) = 0.4. Define the random variable Y = flip number on which the game ends.
(a) Find the probability mass function (pmf) of Y
(b) Determine the cumulative distribution function F (y) = P (Y y) for all y ? R.
(c) Find its expected value, E(Y ) and variance, V (Y ).