Jack & Diane Cossing Toins

Jack and Diane take turns tossing the same coin.   Diane wins if she gets a head before Jack gets a tail.   Jack wins if he gets a tail before Diane gets a head.   Diane goes first.

(a) If the coin is fair, show that the probability that Diane wins is greater than one-half.

Suppose that the probability of getting a head on any one toss is  p.
(b) Find the value of  p for which Jack & Diane have the same probability of winning.
(c) Find the value of  p that maximizes the expected length of the game (i.e., maximizes the expected number of tosses).
(d) Find the value of  p that maximizes the variance of the length of the game.
(e) Find the moment generating function for Y= total # of tosses in the game.