Question

A father is three times as old as his son. After twelve years, his age will be twice that of his son. Find their present ages.

• A. $10,30$
• B. $22,36$
• C. $12,36$
• D. $124,24$

Answer 1

Answer: (C)

$12,36$

Let the son's present age is $x$ years, then the age of the father is $3x$ years.

from the given conditions,
After $12$ years, father's age $2\times (x+12)$
also after $12$ years, father's age is $(3x+12)$
Hence, $2(x+12)=(3x+12)$
$\Rightarrow 2x-3x=12-24$
$\Rightarrow -x=-12$

$\Rightarrow x=12$
At present, Father's age is $12\times 3=36$.
Hence, son's present age is $12$ and father's present age is $36$.