Final answer:
The term "3 meals a day" is a unit rate because it represents the ratio of meals to days, with the correct option being 'It compares 3 meals to 1 day'. Unit rates are useful for comparisons and understanding relationships between quantities.
Step-by-step explanation:
The phrase "3 meals a day" is considered a unit rate because it expresses the ratio of the number of meals to the number of days without mentioning any intermediate values. When we say someone eats 3 meals a day, we are comparing the number of meals they eat to a single day. Thus, the correct option is C which states, 'It compares 3 meals to 1 day'.
In simpler terms, a unit rate gives the measure of quantity per one unit of another quantity. In this case, 'meals' is the first quantity and 'days' is the second quantity. A unit rate is helpful for making comparisons and understanding the relationship between different quantities, such as in budgeting scenarios where you balance food and housing expenses based on available funds, meal planning, or tracking various measurements in daily life or in scientific contexts where units are converted.