What is the probability of rolling a sum of 11 or 7 on a pair of number cubes?

Question

statistical probability

Answer 1

P(rolling a total of 11 or 7 on a pair of fair, 6-sided die, numbered 1 through 6)

How many ways to roll 11?

first die, second die

5,6

6,5

2 ways

How many ways to roll 7?

1,6

2,5

3,4

4,3

5,2

6,1

6 ways

How many ways to roll 11 or 7?

2 + 6 = 8 ways

How many ways to roll anything?

6 * 6 = 36

# ways you want / # ways anything can happen

8 / 36 = 2 / 9 = 0.22222

P(roll 11 or 7 ) = about 0.2222