If a shirt that originally costs $50 is on sale for 20% off, what is the sale price?

Two ways to solve: (1) Calculate the discount, then subtract: 20% of $50 = 0.20 × $50 = $10 discount; $50 - $10 = $40 sale price. (2) Calculate the percent remaining and multiply: 100% - 20% = 80% remaining; 80% of $50 = 0.80 × $50 = $40 sale price. Method 2 is often faster on the ASVAB. Be careful with percent problems: '20% off' and '20% of' are different. '20% off' means subtract 20%; '20% of' means just calculate that percentage. Multi-step problems may involve discount then tax: $40 (sale price) + 8% tax = $40 × 1.08 = $43.20. Or sequential discounts: 20% off then 10% off is NOT 30% off — apply each successively: $50 × 0.80 × 0.90 = $36. The ASVAB often includes problems with sequential percentages, which trip up test-takers who try to combine them incorrectly.