You play a dice game with two dice. If you roll at most 5 (i.e. the sum of the two numbers is 2, 3, 4 or 5) then you win, if you roll 7 or 10 then you lose, otherwise you have to roll again.
(a) What is the probability that the game ends after exactly four rolls?
(b) What is the expected length of the game?
(c) What is the probability that you will win?