Question

Potato's per-kilogram price has risen from Rs.18 to Rs.25. What should be the percentage reduction in potato use so that expenditure does NOT increase?

• A. 28%
• B. 31%
• C. 22%
• D. 34%

Hint:

Think of it this way: for every Rs. 25 you would now spend, you need to cut back by Rs. 7 to stay at your original cost. $7/25$ is exactly $28/100$.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
When the price of a commodity increases, the consumption must decrease to keep the total expenditure constant. The reduction is calculated based on the increased price to return to the original budget level.

Step 2: Key Formula or Approach:
\[ \text{Percentage Reduction} = \left( \frac{\text{Increase in Price}}{\text{New Price}} \right) \times 100 \]

Step 3: Detailed Explanation:
Initial Price = Rs. 18 New Price = Rs. 25 Increase in Price = $25 - 18 = 7$ To keep expenditure the same: \[ \text{Reduction \%} = \left( \frac{7}{25} \right) \times 100 \] \[ \text{Reduction \%} = 7 \times 4 = 28\% \]

Step 4: Final Answer:
The percentage reduction in potato use should be 28%.