Proportions

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the terms and then solve for the unknown variable.

Front

If a car travels 280 miles in 7 hours, what is the rate of travel in miles per hour?

Back

The rate of travel is 40 miles per hour (280 miles ÷ 7 hours).

Front

If 3 people can complete a project in 7 days, how long will it take 5 people?

Back

It will take approximately 4.2 days for 5 people to complete the project.

Front

What is the formula for direct variation?

Back

The formula for direct variation is y = kx, where k is the constant of variation.

Front

If a recipe calls for 1.5 cups of milk for every 3 cups of flour, what is the ratio of milk to flour?

Back

The ratio of milk to flour is 1:2.

Front

How do you find the missing value in a proportion?

Back

Set up the proportion as a fraction and cross-multiply to find the missing value.

Front

What is the relationship between the number of workers and the time taken to complete a project?

Back

The relationship is inversely proportional; as the number of workers increases, the time taken decreases.

Front

If a recipe is scaled up from 2 cups of flour to 8 cups, how much milk is needed if the original recipe used 1 cup of milk?

Back

4 cups of milk are needed to maintain the proportions.

Front

What does it mean for two quantities to vary directly?

Back

It means that as one quantity increases, the other quantity increases at a constant rate.