Ratios and Rates

A ratio is a comparison of two quantities by division, showing how many times one value contains or is contained within the other.

A unit rate is a ratio that compares a quantity to one unit of another quantity, often expressed as 'per' something (e.g., miles per hour).

To calculate a unit rate, divide the first quantity by the second quantity to find the amount per one unit of the second quantity.

$$\frac{40}{4} = 10$$ miles per hour.

$$\frac{240}{60} = 4$$ dollars per minute.

The ratio of boys to girls is 5:7.

7 to 5 is NOT a correct ratio.

The ratio is 50:75, which simplifies to 2:3.

The first step is to divide both quantities by their greatest common factor.

It means for every 3 parts of one quantity, there are 4 parts of another quantity.