Profit and Loss — A seller sells two tables at ₹ 1500 each. On one table he gains 20%, and on the other he loses 20%. What is the overall result on total cost: profit or loss, and by what percent?

Introduction / Context: Equal and opposite percentages on different cost bases do not cancel out when the selling prices are equal. This classic result shows that a 20% gain on one item and a 20% loss on another (sold at the same price) leads to a net loss.

Given Data / Assumptions:

• SP for both tables = ₹ 1500 each.
• Table 1: +20% profit; Table 2: −20% loss.

Concept / Approach: Recover CPs separately from SP = 1.20 * CP (profit case) and SP = 0.80 * CP (loss case). Sum CPs and compare with total SP to compute the overall percentage result on cost.

Step-by-Step Solution:

Verification / Alternative check: The “equal percentage gain & loss” rule around equal SPs always yields a loss because the higher CP in the loss case dominates.

Why Other Options Are Wrong: 4% profit and “neither” contradict the calculation; 10% or 2% loss are incorrect magnitudes.

Common Pitfalls: Averaging +20% and −20% to get 0%—invalid because bases (costs) differ.

Final Answer: 4% loss