Question

If a die is rolled twice in succession and that face vaule of the two rolls are added together. Compute the probability of the sum is grester than 7

Answer 1

15/36 = 5/12 = 41.66%

Explanation:

If a die is rolled twice in a row, and the up face value of both throws are added, that's basically like if you had thrown 2 dice at the same time.

If you throw 2 dice at the same time, there are 36 possible outcomes, from (1,1), (1,2)... to (6,5), (6,6).

You just then have to calculate how many combinations are greater than 7. We have (2,6), (3,5), (3,6), (4,4), (4,5), (4,6), (5,3), (5,4), (5,5), (5,6), (6,2), (6,3), (6,4), (6,5) and (6,6)... a total of 15 values above 7.

So, the probability is 15 totals >7 out of 36 possible outcomes:

15/36 = 5/12 = 41.66%