Solve 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

What is the ratio of cats to dogs if there are 3 cats for every 5 dogs?

Back

The ratio of cats to dogs is 3:5.

Front

If there are 25 dogs in a shelter with a cat-to-dog ratio of 3:5, how many cats are there?

Back

15 cats.

Front

If a 12-ounce shampoo bottle lasts 16 weeks, how long will an 18-ounce bottle last?

Back

24 weeks.

Front

What is the formula for finding the unit rate?

Back

Unit rate = Total amount / Number of units.

Front

If Ernesto can make 2 flags in 3 hours, how long will it take him to make 5 flags?

Back

7.5 hours.

Front

How do you find the cost per pound if 3 pounds of hamburger costs $6?

Back

Cost per pound = Total cost / Total pounds = $6 / 3 = $2 per pound.

Front

If Alicia buys 10 pounds of hamburger at $2 per pound, how much will she pay?

Back

$20.

Front

What does it mean to cross-multiply in a proportion?

Back

Cross-multiplying means multiplying the numerator of one ratio by the denominator of the other ratio.