A salary of a person was increased by 15%. If his salary now is Rs. 9936, then what was the initial salary?

Given:

The salary of a person was increased by 15%.

Increased salary is Rs. 9936.

To do: Find the initial salary.

Solution:

Let his initial salary = $x$$x$

increased amount of salary = 15% of $x$ $x$

=$\frac{15}{100}x$

Present salary = Initial salary $+$ Increased salary

= $x + \frac{15}{100}\times{x}$$x+\frac{15}{100}x$ 

=$\frac{100x+15x}{100}$

=  $\frac{100x+15x}{100}$ 

=$\frac{115x}{100}$

Present salary =  9936

$\frac{115x}{100}$

$\frac{115x}{100}$ = 9936

$x = \frac{9936\times100}{115}$

$x = 432\times20$

= $8640$

So his initial salary was  8640