Find the probability of rolling a sum of 7 with three dice?

Answer 1

You have to find out all combinations of dice that give you 7: that would be 1-1-5; 1-2-4; 1-3-3; 1-4-2; 1-5-1; 2-1-4; 2-2-3; 2-3-2; 2-4-1; 3-1-3; 3-2-2; 3-3-1; 4-1-2; 4-2-1; 5-1-1. I hope I didn't miss any, that would be 15 favorable combinations; the total of possibilities with 3 dice is 63 = 216, so the probability is 15/216 = 5/72, or about 6.9%.