1.
In a game two players AA and BB take turns in throwing a pair of fair dice starting with player AA and the total of scores on the two dice, in each throw, is noted. AA wins the game if he throws a total of 66 before BB throws a total of 77, and BB wins the game if he throws a total of 77 before AA throws a total of 66. The game stops as soon as either of the players wins. The probability of AA winning the game is: