Which of the following best defines ratio?

• A. A rate
• B. The relationship between two numbers or amounts
• C. A fraction
• D. A proportion

Answer: (B)

Ratio is about the relationship between two numbers or amounts, showing how one compares to the other. It captures how much of one quantity there is relative to another, like 4:1 or 4/1 for four of one thing to every one of the other. A rate is a specific kind of ratio that compares two different kinds of quantities with a per-unit dimension, such as speed (miles per hour) or price per item. A fraction expresses a part relative to a whole, and while it can represent a ratio, it’s just one way to write a ratio rather than the general concept itself. A proportion is an equation asserting that two ratios are equal, not the relationship between the two quantities in isolation.