Profit and Loss — Two books are sold at ₹ 24 each. On one book the seller gains 20%, and on the other he loses 20%. What is the overall rupee result across both books?

Introduction / Context:
This is the rupee-value variant of the equal and opposite percentage effect. Even with the same selling price for both items, a 20% gain and a 20% loss do not balance; the loss outweighs the gain.

Given Data / Assumptions:

• SP1 = SP2 = ₹ 24.
• Book 1: +20% profit; Book 2: −20% loss.

Concept / Approach:
Convert each selling condition to the underlying cost price (CP). Then sum CPs and compare to total SP to get the overall rupee difference (gain or loss).

Step-by-Step Solution:

Verification / Alternative check:
Percentage-wise: loss% on total cost = 2/50 * 100 = 4% loss (not asked, but consistent with the tables example).

Why Other Options Are Wrong:
“gained Rs. 1/2” contradicts the computed −2; “no profit no loss” is false.

Common Pitfalls:
Averaging +20% and −20% to 0% and concluding no profit/loss, which ignores differing CP bases.

Final Answer:
lost Rs. 2