Profit and Loss – From discounted profit to no-discount scenario: The marked price of an article is Rs 480. The shopkeeper allows a discount of 10% and still gains 8%. If no discount is allowed, what would be his gain percentage?

Introduction / Context:
We first deduce the cost price from the discounted transaction that yields an 8% gain. With cost known, removing the discount increases the selling price to the marked price, letting us compute the new gain percentage.

Given Data / Assumptions:

• MP = Rs 480
• Discount = 10% ⇒ SP with discount = 0.90 * 480 = Rs 432
• Gain with discount = 8%

Concept / Approach:
Gain of 8% means SP = 1.08 * CP ⇒ CP = 432 / 1.08. With no discount, SP = MP = 480. Compute gain on CP accordingly.

Step-by-Step Solution:
CP = 432 / 1.08 = 400No-discount SP = 480Gain% = (480 − 400) / 400 * 100 = 20%

Verification / Alternative check:
Under discount: 400 → 432 is indeed 8% gain; removing discount boosts gain to 20%.

Why Other Options Are Wrong:
18%, 18.5%, and 20.5% do not match the computed ratio; 22% is too high.

Common Pitfalls:
Applying the 10% discount to CP instead of the marked price.

Final Answer:
20%