Profit and Loss – Inferring a discount from “two free chairs at ₹ 80 each” equivalence: I planned to buy 10 chairs at ₹ 200 each (₹ 2000). The trader offered a discount for buying a set of 12 chairs. I calculated that, compared with the normal 10-chair spend, it is as if the 2 extra chairs cost only ₹ 80 each at the discounted 12-chair rate. What is the percentage discount on the list price?

Introduction / Context:
The story encodes the discounted bundle price. We compare the cost of 12 chairs at the discounted rate with the baseline 10-chair spend at list price. The statement “two extra chairs cost ₹ 80 each” at the discounted rate lets us compute the total discounted price for 12 and thereby the per-chair discounted price, which yields the discount percentage.

Given Data / Assumptions:

• List price per chair = ₹ 200
• Baseline planned spend = 10 * 200 = ₹ 2000
• Effective cost of the 2 extra chairs at the discounted 12-chair rate = ₹ 80 each

Concept / Approach:
Discounted total for 12 = ₹ 2000 + 2 * ₹ 80 = ₹ 2160. Discounted per-chair price = 2160 / 12 = ₹ 180. Discount% = (200 − 180) / 200 * 100.

Step-by-Step Solution:
Discounted total for 12 = 2000 + 160 = ₹ 2160Discounted unit price = 2160 / 12 = ₹ 180Discount% = (200 − 180) / 200 * 100 = 10%

Verification / Alternative check:
At 10% discount, unit = ₹ 180 ⇒ 12 chairs = ₹ 2160. Compared with ₹ 2000 for 10, the extra two cost ₹ 160 total ⇒ ₹ 80 each, matching the description.

Why Other Options Are Wrong:
6%, 8%, 12%, 15% do not reconcile the ₹ 2160 total with the stated “₹ 80 each” effect for the extra two chairs.

Common Pitfalls:
Assuming the extra two are literally free; the statement encodes an equivalent comparison, not literal free items.

Final Answer:
10%