Question

What is the probability of rolling a sum of 8 on a standard pair of six-sided dice? express your answer as a fraction or a decimal number rounded to three decimal places, if necessary?

Answer 1

First lets see how many combinations there are that make 8 from the numbers 1-6:

2+6
3+5
4+4
5+3
and 6+2. 

Note: the order does matter, because you roll two die. This means the first die has a number and the second die also has a number. 2 on 1st dice and 6 on 2nd dice would be a different combination than 2 on 2nd dice and 6 on 1st dice.

Now we calculate the probability of getting a number 2 through 6 on the first dice: which is 5/6.

Then calculate the probability of getting a number that pairs up with the first number to make 8: *Note: once you get a number 2 through 6, there is only one other number that you can roll to make 8. This means the probability of getting a match would be 1/6 on the 2nd dice.

Finally, multiply the two fractions we got earlier: 5/6 x 1/6 = 5/36

Your probability would be 5/36 in fraction form, 13.89% in percent form, or 0.139 in decimal form rounded 3 places.

Hope this helps, and May the Force Be With You!

-Jabba the Hut