#1**+2 **

The rule for divisibility by 8 is that, if the last three digits are divisible by 8, then the whole number is divisible by 8

The total number of outcomes is 6^8

Notice that the smallest that the last three digits can be = 111

And the largest that they can be = 666

The number of integers between these two numbers that are divisible by 8 =

floor [ (666 - 111) / 8 ] = 69

So....the number of outcomes that are divisible by 8 = (6)^5 * 69

So the probability = (6)^5 * 69 / (6)^8 = 69 / 6^3 = 69 / 216 = 23 / 72

CPhill Apr 8, 2019