Question

Wheat is now being sold at Rs. 27 per kg. During last month, its cost was Rs. 24 per kg. Find by how much per cent a family should reduce its consumption so as to keep the expenditure fixed.

• A. 10.2%
• B. 12.1%
• C. 12.3%
• D. 11.1%

Hint:

Use a fixed budget and compare how much wheat it buys at the old and new price.

Answer 1

The Correct Option is D

Here's a second way to solve this, using real numbers for the budget instead of a percentage formula.

Pick a convenient common expenditure, say Rs. 216, since it divides evenly by both 24 and 27.

Last month, at Rs. 24 per kg, Rs. 216 would buy $216/24 = 9$ kg of wheat.

Now, at Rs. 27 per kg, the same Rs. 216 buys only $216/27 = 8$ kg.

So consumption falls from 9 kg to 8 kg, a drop of 1 kg. As a percentage of the original 9 kg, that drop is $\frac{1}{9} \times 100 = 11.11\%$.

Let's summarize:

• Same money buys 9 kg at the old price and 8 kg at the new price
• Fall in quantity: 1 kg out of 9 kg
• Percentage cut needed: $\frac{1}{9} \times 100 \approx 11.1\%$

This matches option D, 11.1%, confirming the answer with plain numbers instead of a formula.