When two dice are rolled find the probability of getting a sum less than 10?

There are 36 combinations of two dice. each have 1 to 6

To get 10 or more requires 4 +6, 5 +5, 5 +6 , 6+5, 6 +4, or 6+6, which are 6 combinations, leaving 36-6 = 30 combinations of less than 10

30/36 = 5/6 probability of getting sum less than 10