Question

a father is three times as old as his son after 12 years ,his age will be twice as that of his son then. find their present ages.

Answer 1

$\huge\bold{Solution}$

$<b><i><u>$ let the age of son be x years

present age of father is 3 times as his son age= 3x years

After 12 years the age of son will be = X +12 years

Age of father =3x +12 year

According to question

3x +12 = 2( x+12)

3x +12 = 2x + 24

3x - 2x =24 -12

X = 12

Son's age =12 years

fathers age = 12 * 3 = 36 years

Answer 2

Here is your solution

 let,
the age of son be x years 

present age of father is 3 times as his son age= 3x years 

After 12 years the age of son will be = X +12 years

Age of father =3x +12 year

A/q

3x +12 = 2( x+12)

3x +12 = 2x + 24

3x - 2x =24 -12

X = 12

Hence

Son's age =12 years 

fathers age = 12 * 3 = 36 years

Hope it helps you