Two dice are thrown. Given that the sum is 8, what is the probability that both show the same number?

Explanation

1. 01

   Sum 8: $(2, 6), (3, 5), (4, 4), (5, 3), (6, 2)$, 5 outcomes.

2. 02

   Only $(4, 4)$ is a double: $\frac{1}{5}$.