Question

The salary of an officer is increased by $25\%$. By what percent should the new salary be decreased to restore the original salary?
(a) 5%
(b) 10%
(c) 15%
(d) 20%

Answer 1

Hint: Here, in this given question, we can first of all take the salary as Rs.100. So, when increased by 25%, it will become Rs.125. Then we have to find out what percentage of amount should be decreased from Rs.125 in order to get back Rs.100. This percentage will give us our answer.

Complete step-by-step answer:
In this given question, we are given that an officer’s salary is increased by 25% and we are asked to find out the percentage of the amount that should be decreased by this to get the original salary of the officer.
The process of solving is as follows.
Let the original salary of the officer be Rs.100.
So, when increased by 25%, it becomes $100+\dfrac{25}{100}\times 100=Rs.125$.
So, the increased amount is Rs.125-Rs.100=Rs.25.
Now, we are to find what percentage of Rs.125 is Rs.25 to get our answer.
Let the percentage be x.
So, $\dfrac{x}{100}\times 125=25$
$\Rightarrow x=25\times \dfrac{100}{125}$
$\Rightarrow x=20\%$
Hence, we have got the percentage to be decreased from the new salary to get the original salary to be 20%.
Therefore, the correct option to this given question is option (d) 20%.

Note: In this type of questions, we may take any number or variable as the original amount and calculate the percentage accordingly. This does not hamper our answer because we are asked to find out the answer in terms of percentage and not in terms of the actual amount.