Ratio and Proportion Word Problems

Front

What is a ratio?

Back

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

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

What is a proportion?

Back

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

Tags

CCSS.7.RP.A.2A

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the two ratios and set the products equal to each other.

Tags

CCSS.7.RP.A.3

Front

What is the formula for finding a missing value in a proportion?

Back

If a/b = c/d, then ad = bc, where a, b, c, and d are the values in the proportion.

Tags

CCSS.7.RP.A.3

Front

If 30 out of 50 students like pizza, what is the ratio of students who like pizza to those surveyed?

Back

The ratio is 30:50, which simplifies to 3:5.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

How do you find the expected number of students who like pizza if 190 students are surveyed?

Back

Use the ratio 30/50 = x/190. Cross-multiply to find x = (30 * 190) / 50 = 114.

Tags

CCSS.7.RP.A.3

Front

If a truck travels 160 miles on 20 gallons of gas, what is the rate of miles per gallon?

Back

The rate is 160 miles / 20 gallons = 8 miles per gallon.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

How do you find the gallons needed for a longer trip using a ratio?

Back

Set up a proportion: 160 miles/20 gallons = 400 miles/x gallons. Cross-multiply to find x = (20 * 400) / 160 = 50 gallons.

Tags

CCSS.7.RP.A.3

Front

What does a scale drawing represent?

Back

A scale drawing represents an object in proportion to its actual size, using a specific ratio.

Tags

CCSS.7.RP.A.2C

Front

If a scale is 4 cm:9 ft, how do you find the actual size from the drawing?

Back

Use the ratio: 4 cm/9 ft = 11 cm/x ft. Cross-multiply to find x = (9 * 11) / 4 = 24.75 ft.

Tags

CCSS.7.RP.A.2C