Consider the following game: A player rolls two dice. If he rolls 7 or less then he loses the game. Otherwise, he selects at random as many cards from the full deck as the sum of the numbers that came up on the dice. The player wins if all four Aces are among the selected cards.

(a) What is the winning probability for this game?

(b) Someone tells that he played this game once and won. What is the probability that he rolled a sum of 10?