Question

Five year ago a man was seven times as old as his son. Five year hence, the father will be three times as old as his son. Fins their present age.

Answer 1

Answer:

let the age of son be x

therefore the age of the father be 7x

according to question

five years back the age of son = (x-5)

and age of father = (7x-5)

=> x-5 = 7x-5 --------(1)

according to sec condition

x+5 = 3x+5 ------------(2)

from here use your own brain

Answer 2

Solution

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 - 16

         ⇒ 4x = 20

         ⇒ x = 5

Let us verify our answer,

        ⇒ 7 × 5 + 10 = 3 (5 + 10)

        ⇒ 35 + 10 = 3×5 + 3×10

        ⇒ 45 = 15 + 30

        ⇒ 45 = 45

LHS = RHS

Hence it is verified.

   

    ⇒ 7x = 7 × 5 = 35

    ⇒ x+5 = 5 + 5 = 10

    ⇒ 7x + 5 = (7 × 5)+ 5 = 35 + 5 = 40