Question

$10$ years ago, the average age of a family of $4$ members was $24$ years. Two children having been born (with age difference of $2$ years), the present average age of the family is again $24$ years. Then the present age of the youngest child is:

• A. $1$ year
• B. $2$ years
• C. $3$ years
• D. $4$ years

Answer 1

The correct option is C $3$ years

Present total age of $4$ members $=24\times 4=96+(10\times 4)=136$
Preset total age of $6$ members (including $2$ children) $=24\times 6=144$
So sum of the ages of the two children $=144-136=8$ yrs.
Thus the ages of the children will be $5$ yrs and $3$ yrs.
As $(5+3=8$ and $5-3=2)$
So, the youngest child's age is $3$ years old.