- How do I calculate the sale price from a discount percentage?
- Sale Price = Original Price × (1 − Discount / 100). A $80 item at 25% off: $80 × 0.75 = $60. Savings = $80 − $60 = $20.
- How do I find the discount percentage when I know both prices?
- Discount % = (Original Price − Sale Price) / Original Price × 100. If a $120 item is selling for $90, the discount is ($120 − $90) / $120 × 100 = 25%.
- How do stacked discounts work?
- Stacked (sequential) discounts are not simply added together. A 20% discount followed by a 10% discount equals a 28% total discount, not 30%. The second discount applies to the already-reduced price. Combined rate = 1 − (1 − d1) × (1 − d2).
- Why is 20% off + 10% off not 30% off?
- Because the second discount is calculated on the reduced price. On a $100 item: 20% off gives $80, then 10% off $80 gives $72. Total savings = $28, or 28% of the original price — not 30%.
