Question

The salary of a man is first increased by \(10\%\) and then again by \(10\%\). But atlast, for some unknown reason, for the third time the salary is decreased by \(20\%\). By what percent the initial salary is changed?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Let the original salary be Rs. 10x
First time, when the salary is increased by $10\%$ it becomes = 110x
2nd time, when it is increased again in by $10\%$ it becomes = Rs. 110x + 11x = 121x
3rd time, when it is decreased by $20\%$ it becomes
$=Rs.121x-\frac{20}{120}$ of Rs. 121x
=Rs. (121x - 24.20x) = Rs.96.80x
$\therefore$ Final change in salary = Rs. 100x - Rs. 96.80x = Rs. 3.20x
$\therefore$ Change p.c. = $\frac{totalchange}{original}\times 100=\frac{3.20x}{100x}\times 100=3.20=3\frac{1}{5}$
$\therefore 3\frac{1}{5}\%$ is decreased.