Wheat price rises from ₹24/kg to ₹27/kg: By what percentage should a family reduce consumption to keep expenditure unchanged?

Introduction / Context:
For a fixed budget, quantity purchased is inversely proportional to price. When price increases, quantity must decrease by the reciprocal factor to maintain constant expenditure.

Given Data / Assumptions:

• Old price = ₹24/kg; new price = ₹27/kg.
• Expenditure remains constant.

Concept / Approach:
New quantity factor = old price / new price = 24/27 = 8/9. The percentage reduction equals 1 − (new factor) expressed in percent.

Step-by-Step Solution:
Quantity factor = 24/27 = 8/9 ≈ 0.888…Reduction = 1 − 8/9 = 1/9 ≈ 0.111…Percentage reduction ≈ 11.1%

Verification / Alternative check:
Suppose original buy = 9 kg (cost = 9*24 = 216). New price 27 ⇒ affordable qty = 216/27 = 8 kg, which is 1 kg less on a base of 9 kg = 11.11%.

Why Other Options Are Wrong:
10.2%, 12.1%, 12.3%, 9.1% do not represent the exact 1/9 reduction required by the price ratio 24:27.

Common Pitfalls:
Comparing absolute rupee differences rather than ratios; percentage change must be computed on quantity, given a fixed expenditure constraint.

Final Answer:
11.1%