Question

A man’s petrol bill in July is Rs. 200. In August, the price of petrol increases by 10% and his consumption is reduced by 10%. Find his petrol bill in August.

• A. Rs. 190
• B. Rs. 210
• C. Rs. 200
• D. Rs. 198

Hint:

When dealing with percentage increases and decreases, always remember to use the ratios and apply them to the original bill to get the final amount.

Answer 1

The Correct Option is D

Given: - The price of petrol increases by 10%, so the new price becomes: \[ \text{New price} = 100 + 10% = 110 \, \text{(in percentage terms)}. \] - The consumption is reduced by 10%, so the new consumption becomes: \[ \text{New consumption} = 100 - 10% = 90 \, \text{(in percentage terms)}. \] We are given that the original petrol bill in July was Rs. 200. This bill is calculated by: \[ \text{Petrol bill} = \text{Price} \times \text{Consumption} = 100 \times 100 = 10000. \] Now, for August: - The new price is Rs. 110, and the new consumption is 90. Thus, the petrol bill in August will be: \[ \text{Petrol bill in August} = 110 \times 90 = 9900. \] The ratio of change in price and consumption is: \[ \frac{100}{99} = \frac{100}{200}. \] This gives: \[ 99 \times 2 = 198. \] So, the correct answer is (d) Rs. 198. Final Answer: The correct answer is (d) Rs. 198.