Recover marked price from difference between two discount schemes On a marked price M, the difference between the selling price with a single 30% discount and with two successive discounts of 20% and 10% is ₹ 72. Find the marked price M.

Introduction / Context:
Two different discount schemes produce two different selling prices. The given rupee difference between those selling prices allows us to back-calculate the marked price. This is a classic application of percentage multipliers.

Given Data / Assumptions:

• Scheme A: single 30% discount ⇒ selling price SP_A = 0.70 * M.
• Scheme B: successive 20% and 10% ⇒ SP_B = 0.80 * 0.90 * M = 0.72 * M.
• SP_B − SP_A = ₹ 72.

Concept / Approach:
Compute the difference factor and equate to ₹ 72 to solve for M: (0.72 − 0.70) * M = 0.02 * M = 72 ⇒ M = 72 / 0.02.

Step-by-Step Solution:
Difference factor = 0.72 − 0.70 = 0.02.0.02 * M = 72 ⇒ M = 72 / 0.02 = 72 * 50 = ₹ 3,600.

Verification / Alternative check:
SP_A = 0.70 * 3600 = 2520; SP_B = 0.72 * 3600 = 2592; Difference = 2592 − 2520 = 72, as required.

Why Other Options Are Wrong:
Other values do not satisfy a 2% difference equal to ₹ 72; for example at ₹ 3,000 the difference would be ₹ 60, not ₹ 72.

Common Pitfalls:
Adding discounts or misordering successive discounts. Always convert to multiplicative price factors to avoid mistakes.

Final Answer:
3,600