Question

Please explain in detail with a proper answer.

A pair of dice is rolled. If you know one of the dies shows a 5, what is the probabiility that the sum is 8.

Answer 1

5/36

Explanation:

So a pair of dice is rolled. 2 dices. A dice has 6 numbers (1,2,3,4,5,6).

Now draw a sample space.

1 2 3 4 5 6

1 2 3 4 5 6 7

2 3 4 5 6 7 8

3 4 5 6 7 8 9

4 5 6 7 8 9 10

5 6 7 8 9 10 11

6 7 8 9 10 11 12

It's asking for SUM, so we plus. Thats why you see this.

So look for all the 8's in the sample space. Theres one in (6,2), (5,3), (4,4), (3,5) and (2,6). Thats 5. We divide that with the total. The total is 36 because there are 36 possible values. so 5/36