Question

The salary of an officer is increased by $25\%$. By what percent should the new salary be reduced to restore the original salary?

Answer 1

Let's consider the salary of the officer $=100$

So, if the salary is increased by 25% then new salary $=100+\frac{25}{100}\times 100$

$=100+25$

$=125$

So, his new salary is 125

To make his salary original 25 must be subtracted from 123, then his salary will be 100 or original salary

So,

% decrease $=\frac{25}{125}\times 100$

$=\frac{1}{5}\times 100$

$=20$

Hence 20% of his new salary must be deducted so that his salary becomes original salary.