A pair of fair dice is rolled. What is the probability of each of the following? (a) the sum of the numbers shown uppermost is less than 7 (b) at least one 1 is cast
a - [1 +2 +3+ 4 +5] =15 / 6^2 =5 / 12
b = 2 nCr 1 * 5^1 + 2 nCr 2 * 5^0 =11 / 6^2 =11 / 36
