Markup then discount net profit: A shopkeeper marks an article 50% above cost and allows a 30% discount to customers. What is his profit percentage?

Introduction / Context:
Another chained-percentage question. Apply markup to move from CP to MP, then discount to move from MP to SP. Compare SP with CP to get profit% or loss%.

Given Data / Assumptions:

• Markup = 50% ⇒ MP = 1.50 * CP
• Discount = 30% ⇒ SP = 0.70 * MP

Concept / Approach:
Compute SP factor relative to CP: SP = 1.50 * 0.70 * CP = 1.05 * CP. Profit% is then (1.05 − 1)*100% = 5%.

Step-by-Step Solution:

Verification / Alternative check:
Direct factor method: 1.50 * 0.70 = 1.05 ⇒ 5% profit.

Why Other Options Are Wrong:
10%, 12%, 15% do not follow from the exact multiplicative combination of 50% and 30%.

Common Pitfalls:
Adding percentages 50 − 30 = 20 and calling that profit. Percentages chain multiplicatively.

Final Answer:
5%