Two standard fair six-sided dice are rolled and the two scores are added. How many of the 36 equally likely outcomes give a total of 7, and what is the probability of that total as a fraction out of the 36 outcomes?

Erklärung

The pairs totalling 7 are 1 with 6, 2 with 5, 3 with 4, 4 with 3, 5 with 2 and 6 with 1, which is 6 of the 36 pairs, so the probability counts those 6 against 36. Counting only 3 pairs treats 1 with 6 as the same result as 6 with 1, but the dice are separate objects and the sample space of 36 already keeps those cases apart.