Ben rolls two number cubes. What is the probability that the sum of the numbers he rolls is less than 6

There are 6 faces on each dice and the total possible combinations possible = 6*6 = 36 combinations.

Of those 36 combinations, the combinations of sum less than 6 are:

1&1 2&1 3&1 4&1

1&2 2&2 3&2

1&3 2&3

1&4

Thus, 10/36 : - )