Question

In $12$ years, a man will be three times as old as his son; the difference of their present ages is $30$ years. Find their present ages.

• A. $33$ years and $3$ years
• B. $50$ years and $10$ years
• C. $42$ years and $12$ years
• D. $33$ years and $12$ years

Answer 1

The correct option is A $33$ years and $3$ years

At present, let son's age be $x$.

Then, father's age will be $30+x$.

$12$ years hence,

Son's age will be $x+12$ and father's age will be $30+x+12=x+42$.

Then according to problem, we have

$42+x=3(x+12)$

$\Rightarrow 42+x=3x+36$

$\Rightarrow 2x=6$

$\Rightarrow x=3$

Therefore, age of son is $3$ years.

Now, age of father will be $30+x=33$ years.