The ratio of ages of son and father is 1 : 9. After 12 years the ratio becomes 1 : 3, then the present age of the son is
1
16 years
2
48 years
3
36 years
4
4 years
The ratio of ages of son and father is 1 : 9. After 12 years the ratio becomes 1 : 3, then the present age of the son is