Question

The average of $3$ friends is $32$ years. If age of $4th$ friend is added their average comes to $31$ years. What is age of fourth friend?

Answer 1

The average age of $3$ friends is $32$ years.

$\therefore$ Total age of $3$ friends $=3\times 32=96years$

The average age of $4$ friend is $31years$

$\therefore$ Total age of $4$ friends $=4\times 31=124years$

$\Rightarrow$ Required age $=(124-96)years=28years$