Chapter 4 - Proportions, Percents, and Solving Inequalities - 4.2 - Percents and Problem Solving - Problem Set 4.2 - Page 155: 18

60%

We know the following equation: $n=\frac{a}{b} \times 100$. In this problem, we are asked to find what percent of b (120) is a (72). n is the percent (which is what we want to find). Thus, we obtain: $ \frac{72}{120} \times 100 = 60$%