Roll two dice. What is the probability to roll a sum of greater than 9 and/or a multiple of 6

Fraction answer plz

Guest Jun 5, 2017

#1**+1 **

Sums > 9 include

10 = 3 ways to do this

11 = 2 ways to do this

12 = 1 way to do this

6 ways to roll a sum > 9

Multiples of 6

6 = 5 ways to do this

12 = 1 way to do this

6 ways to roll a multiple of 6

And we have 36 possible outcomes

So, N (sum > 9 and multiple of 6) = 1 way [rolling a 12 ]

And the P(sum > 9 and multiple of 6) = 1/36

And N ( sum > 9 or multiple of 6 ) = N(sum > 9) + N(multiple of 6) - N(sum > 9 and multiple of 6) =

6 + 6 - 1 = 11 ways

So ... P(sum > 9 or multiple of 6) = 11/36

CPhill
Jun 5, 2017