Question

The mean of 6 numbers is 24. If one number excluded, the mean of remaining numbers becomes 22. Find the excluded number.

Answer 1

Let the sum of $6$ numbers be $x$
Mean $=24$
$\frac{x}{6}=24$
$\therefore x=144$
One number is excluded, so, $5$ numbers.
sum of $5$ numbers be $y$
$\Rightarrow \frac{y}{5}=22$
$y=110$
Thus, $x-y=144-110=34$ is the excluded number.