A retailer buys an item for $80 and sells it for $100. What is the profit as a percentage of cost?
Profit is $20. Percentage profit is measured against cost: 20 ÷ 80 = 0.25, so 25%. Answering 20% means you divided by the selling price by mistake.
Q4Data Insights
Data sufficiency. Is x greater than 10? (1) x > 8 (2) x is a multiple of 6 and x < 15
(1) alone allows x = 9, so no. (2) alone allows 6 or 12, so no. Together, x must be a multiple of 6 that is above 8 and below 15 — only 12, which is above 10. So both are needed.