Question

How do you determine the number of ways a computer can randomly generate two distinct integers whose sum is 8 from 1 through 12?

Answer 1

7

Explanation:

You have to check each possibility for the first integer, and find what the second integer must be to match the sum
1 : the second must be 7 : (1,7)
2 : the second must be 6 : (2,6)
3 : the second must be 5 : (3,5)
4 : the second must be 4 : (4,4)
5 : the second must be 3 : (5,3)
6 : the second must be 2 : (6,2)
7 : the second must be 1 : (7,1)
8 or more : impossible