Introduction
In many shopping or business scenarios, an item is sold at a discount on its marked price (MP). This type of problem is very common in aptitude tests.
The key idea is that the discount is always calculated on the marked price. The final selling price (SP) is the marked price minus the discount amount.
Pattern: Discount on Marked Price (Single Discount)
Pattern
The shopkeeper reduces the marked price by a certain percentage to arrive at the selling price.
Formula: Selling Price = Marked Price × (1 - Discount%/100)
Discount Amount: = Marked Price × (Discount% ÷ 100)
Step-by-Step Example
Question
A shirt has a marked price of ₹1,200. The shopkeeper offers a discount of 15%. Find the selling price.
Options:
- A. ₹1,000
- B. ₹1,010
- C. ₹1,020
- D. ₹1,030
Solution
-
Step 1: Identify marked price and discount.
Marked Price (MP) = ₹1,200, Discount = 15%. -
Step 2: Compute the discount amount.
Discount amount = (15 ÷ 100) × 1200 = ₹180. -
Step 3: Subtract discount from MP to get SP.
Selling Price = MP - Discount = 1200 - 180 = ₹1,020. -
Final Answer:
₹1,020 → Option C -
Quick Check:
85% of 1200 = 0.85 × 1200 = 1020 ✅
Quick Variations
- If discount is 25% on ₹800 → SP = 75% of 800 = ₹600.
- If discount is 10% on ₹1,500 → SP = 90% of 1500 = ₹1,350.
- If discount is 12.5% on ₹2,000 → SP = 87.5% of 2000 = ₹1,750.
Trick to Always Use
- Shortcut: Selling Price = (100 - d)% of Marked Price.
- Tip: Use complement % to avoid subtraction mistakes (e.g., for 20% discount, SP = 80% of MP).
- Memory Aid: Always apply discount on MP, not on cost price or profit price.
Summary
Summary
- Compute discount amount: Discount = MP × (d ÷ 100).
- Find selling price: SP = MP - Discount or SP = MP × (1 - d/100).
- Use complement percent (100 - d)% to calculate SP quickly.
- Always apply the discount on the Marked Price (MP), not on CP or SP).
Example to remember:
MP = ₹1,200, d = 15% → SP = ₹1,200 × 0.85 = ₹1,020.
