Comparing single vs successive discounts: On a marked price, the difference between selling prices under a flat 30% discount and under two successive discounts of 20% and 10% is ₹72. Find the marked price.

Introduction / Context: Successive discounts multiply, not add. A flat 30% reduces price to 70% of MRP, whereas 20% followed by 10% reduces to 0.8 * 0.9 = 72% of MRP. Their difference times MRP equals the given rupee gap, allowing quick back-calculation of the MRP.

Given Data / Assumptions:

• Single discount: 30% ⇒ SP1 = 0.70 * M.
• Successive discounts: 20% then 10% ⇒ SP2 = 0.8 * 0.9 * M = 0.72 * M.
• SP2 − SP1 = ₹72.

Concept / Approach: Compute the difference factor: 0.72M − 0.70M = 0.02M. Set 0.02M = 72 and solve for M. This avoids any cost price involvement since only selling prices from M are compared.

Step-by-Step Solution:

Verification / Alternative check: SP1 = 0.70 * 3600 = ₹2520; SP2 = 0.72 * 3600 = ₹2592; difference = ₹72, as required.

Why Other Options Are Wrong: ₹3000, ₹2500, ₹2400, ₹2800 do not produce a ₹72 gap under the specified discount schemes.

Common Pitfalls: Adding discounts (20% + 10% = 30%) incorrectly; successive discounts multiply and are not simply additive.

Final Answer: ₹ 3600