Question

A man got a 10% increase in his salary. If his new salary is Rs. 1,54,000. Find his original salary.
A. RS. 140000
B. Rs. 144000
C. Rs. 240000
D. RS. 120000

Answer 1

Hint: First of all we assume the original salary of man to be Rs.x. After this we calculate the 10% of the original salary and then add it to the original salary to get the new salary in terms of ‘x’. Finally, equate it with the given new salary to get the equation.

Complete step-by-step answer:

Let us assume that the original salary of man is Rs.x.
It is given that there is a 10% increment in his salary.
\[\therefore \] The incremental amount = 10% of Rs. x = \[\dfrac{{10}}{{100}} \times {\text{Rs}}{\text{.x = Rs }}\dfrac{{\text{x}}}{{10}}\]
New salary = Original salary + Increment
Putting the values in above expression, we get:
New salary = ${\text{Rs}}{\text{. x + Rs}}{\text{. }}\dfrac{{\text{x}}}{{10}}{\text{ = Rs}}{\text{.}}\left( {{\text{x + }}\dfrac{{\text{x}}}{{10}}} \right) = {\text{Rs}}{\text{.}}\dfrac{{11{\text{x}}}}{{10}}$
According to question:
$\dfrac{{11{\text{x}}}}{{10}} = 154000$
$ \Rightarrow {\text{x = 154000}} \times \dfrac{{10}}{{11}}$ =140000
Therefore, the original salary = Rs. 1,40,000.
So, option A is correct.

Note: In this type of question, you should know the meaning of percentage and how to calculate the given percentage of some given quantity. Percentage is just part of 100. So, we can write it in terms of a fraction whose denominator is 100. For example 10% = $\dfrac{{10}}{{100}}$. To calculate x% of some quantity, first convert the percentage into fraction and then multiply it with the given quantity.