Question

After five years the age of a father will be twice the age of his son, whereas five years ago, he was seven times as old as his son was. What is father's present age?

Answer 1

let age of father be X and age of son be y then age of father after 5years will be (x+5) years and age of son after 5years will be (y+5) years

according to question father age is twice

on comparing ages of father and son ages

x+5 =2(y+5)

x+5=2y+10

x-2y=5 equation 1

and age of father before 5years will be x-5year and age of son before 5years will be y-5years

on comparing (x-5)=7(y-5)

x-5=7y-35

x-7y =-35+5

x-7y =-30 equation 2

on comparing equation 1 and 2 equation we found that y=7years and x=19years then age of father be 19years