Since m > 3 and n > 5, suppose we take m and n to be the smallest possible integers, m = 4 and n = 6. Then
3m + 5n - 2k = 42 - 2k
which is minimized by the largest value that k can take, k = 5. So the minimum value of 3m + 5n - 2k would be 32.
6.6m questions
8.7m answers