Question

A 8-sided die is rolled twice. If the same number comes up both times we say that "doubles" was rolled. If at least one 3 was rolled, what is the probability that doubles was roll

Answer 1

`(1)/(15)`

Explanation:

A 8-sided die is rolled twice and at least one 3 was rolled. So, the total possible outcomes are

(3,1),(3,2),(3,3),(3,4),(3,5),(3,6),(3,7),(3,8),(1,3),(2,3),(4,3),(5,3),(6,3),(7,3),(8,3)

If the same number comes up both times we say that "doubles" was rolled.

Total favorable outcomes = {3,3}

Total number of favorable outcomes = 1

We need to find the probability that doubles was roll.

`Probability=\frac{\tex{Favorable outcomes }}{\text{Total outcomes}}`

`Probability=(1)/(15)`

Therefore, the probability that doubles was roll is
`(1)/(15)`.