The present ages of 'P' and 'Q' are in the ratio of 3 : 7 respectively. 'm' years ago, ages of 'P' and 'Q' were in the ratio of 1 : 3 respectively. If the ages of 'P' and 'Q' are integers, then how many values of 'm' is possible, given that the present ages of both 'P' and 'Q' are less than 50 years?
1
5
2
6
3
7
4
8
5
9