Answer:
89
Step-by-step explanation:
I took the same exact test 9
28: 1, 2, 4, 7, 14, 28
40: 1, 2, 4, 5, 8, 10, 20, 40
The common factors are 1, 2, and 4.
You can use a factor rainbow to help you find the factors (:
The first choice can be any one of the 8 side dishes.
For each of these . . .
The 2nd choice can be any one of the remaining 7.
Total number of ways to pick 2 out of 8 = (8 x 7) = 56 ways .
BUT ...
That doesn't mean you can get 56 different sets of 2 side dishes.
For each different pair, there are 2 ways to choose them . . .
(first A then B), and (first B then A). Either way, you wind up with (A and B).
So yes, there are 56 different 'WAYS' to choose 2 out of 8.
But there are only 28 different possible results, and 2 'ways'
to get each result.