Next section: Conditional probability

The same principle can be applied to the problem of determining the probability of obtaining different totals from a pair of dice. As shown below, there are 36 possible outcomes when a pair of dice is thrown.

To calculate the probability that the sum of the two dice will equal 5, calculate the number of outcomes that sum to 5 and divide by the total number of outcomes (36). Since four of the outcomes have a total of 5 (1,4; 2,3; 3,2; 4,1), the probability of the two dice adding up to 5 is 4/36 = 1/9 . In like manner, the probability of obtaining a sum of 12 is computed by dividing the number of favorable outcomes (there is only one) by the total number of outcomes (36). The probability is therefore 1/36 .

Next section: Conditional probability