You toss two number cubes. If a sum of 7 or 11 comes up, you get 7 points, if not you lose 2 points. The probabilities for each of the sums is: P(2) = 1/36 P(3) = 1/18 P(4) = 1/12 P(5) = 1/9 P(6) = 5/36 P(7) = 1/6 P(8) = 5/36 P(9) = 1/9 P(10) = 1/12 P(11) = 1/18 P(12) = 1/36 The probability of a sum of 7 or 11 is: 1/36 1/18 2 / 9 1/36