Two six-sided number cubes are rolled. Each number cube has sides numbered 1 through 6. What is the probability that the outcome is a sum that is a prime number or a multiple of 4. Give the answer in simplest fraction form.
According to my count, there are 24 combinations that will give you either a Prime number or a Multiple of 4:
So, 24 / 6^2 =24 / 36 = 2/3 - probability.
Here is a table of outcomes
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
We have 15 prime oucomes and 9 outcomesthat are multiples of 4
So....as the Guest said [ 15 + 9 ] / 36 = 24 / 36 = 2 /3
+309 
