Adam's art gallery bought a photograph for $250 and marked the price up 40%. What was the amount of the mark-up?

1. Let m equal the amount of mark-up. 2. The mark-up is 40% of the original cost, so m equals 0.40 times 250. 3. Multiplying gives m equals 100. 4. The mark-up on the photograph was $100. _Source: OpenStax Elementary Algebra (CC BY 4.0), Ch 3 "Math Models", section 3.2 Solve Percent Applications_