Last year, Ranjan’s monthly salary was ₹34,500 and this year his monthly salary is ₹38,640. What is the percentage increase in Ranjan’s monthly salary this year over his monthly salary last year?

The correct option is 12%.

To find the percentage increase in Ranjan’s monthly salary, we can follow these steps:

Step 1: Identify the original and new salary values.
Last year's monthly salary (Original value) = ₹34,500
This year's monthly salary (New value) = ₹38,640

Step 2: Calculate the increase in salary.
$\text{Increase in salary}=\text{New salary}-\text{Original salary}$
$\text{Increase in salary}=\mathrm{38,640}-\mathrm{34,500}=\mathrm{4,140}$

Step 3: Calculate the percentage increase.
The formula for percentage increase is given by:
$\text{Percentage Increase}=\left(\frac{\text{Increase in salary}}{\text{Original salary}}\right)\times 100$

Substitute the values into the formula:
$\text{Percentage Increase}=\left(\frac{\mathrm{4,140}}{\mathrm{34,500}}\right)\times 100$

$\text{Percentage Increase}=\frac{\mathrm{4,140}}{345}=12\%$

Hence, the percentage increase in Ranjan’s monthly salary is 12%.