2.4 Backgammon:  Backgammon is a board game for two players in which the playing pieces are moved according to the roll of two dice. Players win by removing all of their pieces from the board, so it is usually good to roll high numbers. You are playing backgammon with a friend and you roll two 6's in your first roll and two 6's in your second roll. Your friend rolls two 3's in his first roll and again in his second row. Your friend claims that you are cheating, because rolling double 6's twice in a row is very unlikely. Using probability, show that your rolls were just as likely as his.