Question

The sum of the ages of a father and a son is 56. Four yrs ago the father was 3 times as old as the son. Find the current age of them both.

Answer 1

let x is father and y is son

x+y=56

x=56-y

x=3y

(56-y)-4=5(3y-4)

52-y=15y-20

52+20=15y+y

72=16y

y=72/16

y=4year with 6month

y=4.5+4=8.5yr "current age"

x=3(4.5)

=13.5 year

×=13.5+4

x=17.5 yr "current age"

Answer 2

I think the current age of the child is 16 and the father is 40. That would mean 4 years ago the father was 36 and the child was 12. This makes the father 3 times as old as his son four years ago.