Difficulty: Easy
Correct Answer: 25%
Explanation:
Introduction / Context: When a seller’s revenue for a smaller count equals the cost for a larger count, the per-unit selling price must be higher than the per-unit cost. The ratio directly yields the profit percentage on cost.
Given Data / Assumptions:
Concept / Approach: Let CP per mango = c. Then cost of 20 mangoes = 20c. If selling 16 mangoes fetches 20c, then SP per mango = (20c)/16 = 1.25c, i.e., 25% above cost. Profit% on cost is (SP − CP)/CP * 100 = (1.25c − c)/c * 100 = 25%.
Step-by-Step Solution:
Let CP_unit = c ⇒ Cost(20) = 20c Given SP(16) = 20c ⇒ SP_unit = 20c/16 = 1.25c Profit% = (1.25c − c)/c * 100 = 25%Verification / Alternative check: Use concrete numbers: If c = ₹ 4, cost(20) = ₹ 80. Selling 16 at SP_unit = ₹ 5 gives revenue ₹ 80. Profit per unit = ₹ 1 on a base of ₹ 4 ⇒ 25%.
Why Other Options Are Wrong: 18%, 20%, 16%, and 12.5% do not match the exact 1.25 ratio derived from 20/16.
Common Pitfalls: Subtracting 20 − 16 = 4 and calling it 4% without relating it to the cost base; percent must be ratio-based, not difference-based.
Final Answer: 25%
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