Discount, Marked Price and Successive Discounts

Key terms

• Marked Price (MP): price printed on the tag.
• Discount: reduction on MP. Selling Price (SP) = MP − Discount.
• Discount % is always on MP; profit/loss % is always on Cost Price (CP).

Formulas

• SP = MP × (100 − d)/100
• If a shopkeeper wants profit p% after discount d%: MP/CP = (100 + p)/(100 − d).

Successive discounts

Two discounts a% and b% ≠ (a + b)%. Single equivalent discount = a + b − (a × b)/100.

• 20% and 10% → 20 + 10 − 2 = 28% (not 30%).

Worked example

CP = ₹800. MP is 25% above CP = ₹1,000. Discount 10% → SP = ₹900. Profit = ₹100 = 12.5% of CP.

Exam tips (RRB NTPC)

1. "Buy 3 get 1 free" = 1 free out of 4 = 25% discount.
2. Always confirm the base: discount → MP, profit → CP.

Analogy

A discount is a coupon on the price tag; profit is measured from the shop's purchase bill. Two coupons of 20% and 10% don't add to 30% because the second coupon is applied to the already-reduced price — like cutting 10% off a cake that's already had a 20% slice removed.