Profit and Loss — A man buys two hens for ₹ 500 each. He sells one at a 15% profit and the other at a 5% loss. What is his overall profit percentage on the combined cost?

Introduction / Context:
When costs are equal, the net percentage outcome equals (profit on item 1 − loss on item 2) divided by the combined cost. Because bases are the same (₹ 500 each), arithmetic is straightforward and avoids ratio traps.

Given Data / Assumptions:

• CP1 = CP2 = ₹ 500.
• Outcome 1: +15% ⇒ profit = 0.15 * 500 = 75.
• Outcome 2: −5% ⇒ loss = 0.05 * 500 = 25.

Concept / Approach:
Net profit (rupees) = 75 − 25 = 50. Total cost = 500 + 500 = 1000. Overall profit% = 50/1000 * 100 = 5%.

Step-by-Step Solution:

Verification / Alternative check:
SP1 = 575; SP2 = 475; Total SP = 1050; Total CP = 1000 ⇒ 50 gain ⇒ 5%.

Why Other Options Are Wrong:
10%, 12%, and 15% overstate the net effect; 2% understates it.

Common Pitfalls:
Averaging +15% and −5% to 5% works here only because CPs are equal; in general unequal bases require weighted averaging or rupee balancing.

Final Answer:
5%