Discount Amount = Original × (Discount% ÷ 100) Final Price = Original − Discount Amount Original from Sale = Sale Price ÷ (1 − Discount%/100) Discount % = ((Original − Sale) ÷ Original) × 100 Successive discounts = 100 − (1−d1/100)×(1−d2/100)×100
Successive discount myth: 20% off then 10% off ≠ 30% off. Actual = 1 − (0.80 × 0.90) = 28% total. On ₹1,000: you pay ₹720, saving ₹280, not ₹300.
Frequently Asked Questions
Discount = ₹999 × 20 ÷ 100 = ₹199.80. Final price = ₹999 − ₹199.80 = ₹799.20. You save ₹199.80.
No — successive discounts don't add. 20% then 10% = 1 − (0.80 × 0.90) = 28% total, not 30%. On ₹1,000: you pay ₹720, saving ₹280 not ₹300. This is a common retailer marketing trick.
Original = Sale Price ÷ (1 − discount/100). Example: Paid ₹750 after 25% off → Original = ₹750 ÷ 0.75 = ₹1,000.
Discount % = ((Original − Sale) ÷ Original) × 100. Example: ₹1,000 item sold at ₹799 → ((1000−799)÷1000)×100 = 20.1%.
GST is on the actual transaction value (selling price after discount). If a ₹1,000 item sells at ₹800 with 18% GST, the GST is ₹144 (18% of ₹800), not ₹180 (18% of MRP).