Two number cubes are rolled. Each number cube has sides numbered 1 through 6.
What is the probability that the outcome of the roll is an even sum or a sum that is a multiple of 3?
Here are the outcomes and their frequencies
Outcomes - Frequencies
2 - 1 7 - 6 12 - 1
3 - 2 8 - 5
4 - 3 9 - 4
5 - 4 10 - 3
6 - 5 11 - 2
P ( even or multiple of 3 ) =
P( even) + P(multiple of 3) - P(even and multiple of 3) =
18 / 36 + 12 / 36 - 4/36 =
26 / 36 = 13/18
+523 
