Question

The age of the elder father is twice the age of the elder son. Ten years later the age if the father will be 3 times that of the younger son. If the difference of the ages of the two sons be 15 years, the age of the father is?

Answer 1

Let father's age be F and Elder son's be E and  younger son's be Y.

Accordingly F=2E  , F+10 = 3*(Y+10) and E-Y=15

So, F+10 = 3*(E-15) (since E-Y=15 ⇒ Y=E-15)

     2E+10 = 3*(E-15) (since F=2E)

     2E+10 = 3E-45

     E=55 years

⇒ present age of father F= 110 years