When rolling two standard die there are 36 possibilities. The smallest sum being 2 (rolling a 1,1) and the largest being 12 (rolling a (6,6). Of that range, prime numbers are 2, 3, 5, 7, 11. In the sums there are 1-2's, 2-3's, 4-5's, 6-7's, and 2-11's. P(sum 2 is die prime) = 15/36 = 5/12
