Answer:
40 + 4 + 4 = 48 years (present sum of ages of father and son)
Father : Son : Sum
3 : 1 : 4
4 units = 48 years
1 unit = 48 years ÷ 4
= 12 years
Father's present age = 3 × 12 years - 4 years
= 36 - 4
= 32 years
Son's present age = 12 years - 4 years
= 8 years
