1. The problem asks which ratios from the list are equivalent. 2. Two ratios $a:b$ and $c:d$ are equivalent if their cross products are equal, i.e., $a \times d = b \times c$. 3. Let's check each pair against the others: - a. $24:12$ simplifies to $\frac{24}{12} = 2$. - b. $14:28$ simplifies to $\frac{14}{28} = \frac{1}{2} = 0.5$. - c. $10:5$ simplifies to $\frac{10}{5} = 2$. - d. $18:2$ simplifies to $\frac{18}{2} = 9$. - e. $9:4.5$ simplifies to $\frac{9}{4.5} = 2$. 4. Now compare the simplified values: - a, c, and e all equal 2, so they are equivalent. - b equals 0.5, not equivalent to others. - d equals 9, not equivalent to others. 5. Therefore, the equivalent ratios are a, c, and e. Final answer: Ratios a, c, and e are equivalent.