Explanation:

Number which fully divide by a positive integer x = number - remainder = 732 -12 = 720
720 is fully divide by positive integer x.
Factor of 720 = $$2^4 \times 3^2 \times 5
Total factor = (4 + 1).(2 + 1).(1 + 1) = 5.3.2 = 30
We combinations of these factors which are more than 12 and maximum 720 because remainder is 12.
Combination lees than 13 = 1, 2, 3, 4, 5, 6, 8, 9, 10, 12
Number of combination lees than 13 = 10
Number of values of x = 30 - 10 = 20