Question

Two dice a rolled what is the probability that the sum of the numbers rolled is either 9 or 10 express your answer as a fraction in the lowest terms or a decimal rounded to the nearest millionth

Answer 1

We want to know the probability of getting a sum equal to 9 or a 10 rolling two dices. To find this probability, we must compute the quotient between the number of ways of getting a sum equal to 9 or 10, and the total number of possible results rolling two dices.

• We can get a sum equal to 9 with the following outcomes: (3,6), (6,3), (4,5) and (5,4). So we have 4 possible ways of getting a sum equal to 9.

• We can get a sum equal to 10 with the following outcomes: (4,6), (6,4) and (5,5). So we have 3 possible ways of getting a sum equal to 10.

,

• The total number of possible ways to get a sum equal to 9 or 10 is 4+3 = 7.

• The total number of possible results is 6*6 = 36.

So the probability of getting a sum equal to 9 or 10 rolling two dices is:

`P=\frac{\#\text{ways of getting a sum equal to 9 or 10 }}{\#\text{possible results rolling two dices}}=(4+3)/(36)=(7)/(36)\text{.}`

Answer: 7/36