In the Doubles Game, students can win carnival tickets to spend on games and food. A player pays one ticket to roll two number cubes(six-sided dice). If the numbers match, the player wins five tickets. If a player plays this game 20 times, about how many tickets can he or she expect to win or lose?

Answer 1

P(match) = 1/6
so,

E = 20/6 * 5 - 20 ≈ -3

surprise, surprise -- the house wins. You only win 5/6 ticket per game. But it costs a whole ticket to play.