Mathematics ACT Aspire Practice Test

What defines a unit rate?

1. A ratio with identical units

2. A rate simplified to a denominator of 1 unit

3. A comparison of quantity to size

4. A percentage ratio

The correct answer is: A rate simplified to a denominator of 1 unit

A unit rate is fundamentally defined as a rate that has been simplified to express one of the quantities in terms of a single unit. In practical terms, this means taking a rate that compares two different quantities and reducing it so that one of the quantities is represented as a single unit. For example, if you are looking at a speed of 60 miles per hour, the unit rate here is that you travel 60 miles for every hour, translating to a rate of 60 miles for 1 hour. This definition is crucial in various real-life situations such as converting prices (for example, determining the price per item), understanding speeds, or comparing different quantities efficiently. Understanding unit rates enables better comparisons and helps in decision-making in daily activities and academic problems alike. While the other options provide different interpretations of ratios or rates, they do not capture the core concept of a unit rate as effectively. A ratio with identical units implies no simplification and does not reflect the need for unit normalization, while a comparison of quantity to size is a broader term and does not specifically refer to the simplification aspect. A percentage ratio is focused on a different format of expression and doesn't inherently define the concept of reducing to a denominator of 1.