The monthly income of Chetan is ₹60,000 and his expenditure is ₹35,000. If his income increases by 25%, and his expenditure increases by 15%, then what will be the percentage increase in his savings?

The correct option is 39%.

Let's break down the step-by-step solution to understand why this is the correct answer:

Step 1: Calculate the initial savings.
Savings are calculated as the difference between monthly income and monthly expenditure.
Initial Income = ₹60,000
Initial Expenditure = ₹35,000

$$\text{Initial Savings}=\text{Initial Income}-\text{Initial Expenditure}$$

$$\text{Initial Savings}=\mathrm{60,000}-\mathrm{35,000}=\mathrm{25,000}$$

So, Chetan's initial monthly savings is ₹25,000.

Step 2: Calculate the new income after a 25% increase.
The income increases by 25% of ₹60,000.

$$\text{Increase in Income}=25\%\text{of}\mathrm{60,000}=\frac{25}{100}\times \mathrm{60,000}=\mathrm{15,000}$$

$$\text{New Income}=\mathrm{60,000}+\mathrm{15,000}=\mathrm{75,000}$$

Step 3: Calculate the new expenditure after a 15% increase.
The expenditure increases by 15% of ₹35,000.

$$\text{Increase in Expenditure}=15\%\text{of}\mathrm{35,000}=\frac{15}{100}\times \mathrm{35,000}=\mathrm{5,250}$$

$$\text{New Expenditure}=\mathrm{35,000}+\mathrm{5,250}=\mathrm{40,250}$$

Step 4: Calculate the new savings.
Subtract the new expenditure from the new income:

$$\text{New Savings}=\text{New Income}-\text{New Expenditure}$$

$$\text{New Savings}=\mathrm{75,000}-\mathrm{40,250}=\mathrm{34,750}$$

Step 5: Calculate the percentage increase in savings.
First, find the absolute increase in savings:

$$\text{Increase in Savings}=\text{New Savings}-\text{Initial Savings}$$

$$\text{Increase in Savings}=\mathrm{34,750}-\mathrm{25,000}=\mathrm{9,750}$$

Now, calculate the percentage increase relative to the initial savings:

$$\text{Percentage Increase}=\left(\frac{\text{Increase in Savings}}{\text{Initial Savings}}\right)\times 100$$

$$\text{Percentage Increase}=\left(\frac{\mathrm{9,750}}{\mathrm{25,000}}\right)\times 100$$

$$\text{Percentage Increase}=\frac{\mathrm{9,750}}{250}=39\%$$

Therefore, Chetan's savings will increase by 39%.