Question

Two standard dice are rolled, what is the probability of rolling a total of 9?

Answer 1

`4/36=1/9`

Explanation:

There are 36 possible rolls:

`((color(white)(0),ul1,ul2,ul3,ul4,ul5,ul6),(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))`

and of those, 4 result in a nine. Therefore, the probability of rolling a 9 is:

`4/36=1/9`

Answer 2

`1/4`

Explanation:

If we roll two `6` sided dice, the number of outcomes is equal to

`6xx6`, or `36`. This will be our denominator.

How many ways can we get a `9` with two dice?

We can get the following:

`6,3`

`5,4`

`4,5`

`3,6`

There are four ways of getting `9` with two dice. This will be ur numerator. Thus, we have

`9/36`, which can be simplified to `1/4`.

Therefore, the probability of rolling a `9` with two dice is `1/4`.

Hope this helps!