If m and n are positive integers and 2m + 3n = 15, what is the sum of all possible values of m?
One can write down all possilities:
- m =0 , n= 5
- m cannot take value 1 or 2.
- m= 3, n= 3
- m cannot take value 4 or 5
- m= 6 , n= 1
So the sum 0 + 3+ 6 = 9