Profit and Loss — A showroom sells a leather jacket at ₹ P claiming a 10% profit. At a trade fair, he marks the same jacket at ₹ 2P and allows a 20% discount. What percentage profit does he make at the trade fair (relative to his cost)?

Introduction / Context:
This question compares two pricing strategies on the same cost base. First, the normal sale reveals the cost via a 10% margin. Then, the trade-fair pricing uses a 2P tag and a 20% discount, yielding a new selling price to be compared with the original cost for the revised profit percentage.

Given Data / Assumptions:

• Normal sale: SP_normal = P at +10% ⇒ Cost (CP) = P / 1.10.
• Trade fair: Marked price = 2P; Discount = 20% ⇒ SP_fair = 0.80 * 2P = 1.6P.

Concept / Approach:
Profit factor at fair = SP_fair / CP = 1.6P / (P/1.10) = 1.6 * 1.10 = 1.76. Profit% = (1.76 − 1) * 100 = 76%.

Step-by-Step Solution:

Verification / Alternative check:
Example: If P = 110, CP = 100. Fair SP = 176 ⇒ profit = 76 on 100 ⇒ 76% (confirms).

Why Other Options Are Wrong:
80% and 70% are near but incorrect; 60% understates the effect; “None of these” is unnecessary since 76% is exact.

Common Pitfalls:
Comparing 20% discount directly to 10% profit without adjusting bases; always compute via cost to avoid base confusion.

Final Answer:
76%