Question

Five years ago a man was seven times as old as his son. Five years hence, the father will be three times as old as his son. find their present ages

Answer 1

Let the past age of son = x
Let the past age of father = 7x
So,
Present ages are x+5 and 7x+5
Future age of son = x+10
Future age of father = 7x+10
Given
7x+10 = 3*(x+10)
7x+10 = 3x+30
7x-3x = 30-10
4x = 20
x = 20/4
x = 5
7x = 35


=> Present age of son = x+5 = 10

=> Present age of father = 7x+5 = 40

Answer 2

let age before 5 year =x for man
son's age=x/7
present age x+5 for
son's age =x+35/7
x
given
x+5+5=3(x+35/7+5)




x+35/7=(x+35)/7