Question

The age of father is 40 years more than that of his son. After 5 yers father age will be thrice his son's age. Find their present ages.

Answer 1

Let x be son's age and father's age be x +40.
After 5yrs,
x+40+5 = 3(x+5)
x+45 = 3x + 5
x-3x = - 5-45
- 2x = - 40
x = 40/2
x = 20
Son's present age = 20
Father's present age = 60

Answer 2

Required Solution:

• Let the present age of son be x yrs.
• Let the present age of father be x + 40 yrs.

According to the Question :

After 5 years:

$\rm3 (x +5) = x + 40 + 5 \\ \\ \implies \rm\: 3x + 15 = x + 45 \\ \\ \implies\rm3x - x = 45 - 15 \\ \\ \implies \rm \: 2x = 30 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \therefore \rm \: x = 30$

$\rm{Present \: age \: of \: son \: will \: be \: 15 \: years} \\ </p><p> \rm{Present \: age \: of \: father \: will \: be \: = 15 + 40 = 55 \: years}$