Question

Two dice are rolled to determine the sum. What is the probability that the sum on both dice is 7, given that exactly one die turned up a 5?

Answer 1

it depends on how many sided die it is

Answer 2

One die has a 5.
The only way to get a sum of 7 is by rolling a 2 on the other die.
The other die has 6 equally likely outcomes, the numbers 1, 2, 3, 4, 5, or 6.
The probability of rolling a 2 with one die is 1/6.

The answer is 1/6.