A pair of standard dice is rolled. Find the probability that the sum of the two dice is less than 13

As the largest number possible outcome is (6,6), and their sum is 12, less than 13, we conclude that all the pairs will have sum less than 13.

Thus all the pairs are in the favourable outcomes, and the probability is 1

For standard number cubes (1-6), the maximum answer possible is 12

(=6+6)

So, all possible answers are less than 13, giving a probability of 100%.