Question

A father’s age is four times that of his son. After 5 years, it will be three times that of his son. How many more years will take if father’s age is to be twice that of his son?

Answer 1

Let the son’s age be x years. Then the father’s age will be 4x years.

After 5 years, the son’s age will be 15 years and the father’s age will be 45 years.

After y more years, the father’s age will be twice his son’s age.