7th 2-1 Ratios Rates and Unit Rates

The ratio of boys to girls at a movie is 4 : 7. If there are 21​ girls, how many boys are at the​ movie?

• 12

• 21

• 33

• 8

A store sells a package of 25 trading cards for​ $5.25. What is the unit price per​ card?

• 4.76

• .21

• 131.25

• .25

What is the unit rate for meters per second if a car travels 374 meters in 17​ seconds?

• 21

• 6358

• .045

• 22

A toy​ store, the ratio of the number of dolls to the number of teddy bears is 6 : 5. If the store has 240​ dolls, how many teddy bears are in the​ store?

• 300

• 288

• 200

• 242

An airplane on autopilot took 5 hours to travel​ 3,475 kilometers. What is the unit rate for kilometers per​ hour?

• 735

• 695

• 17,375

• .0014

At a​ supermarket, a​ 6-ounce bottle of brand A salad dressing costs​ $1.56. A​ 14-ounce bottle costs​ $3.36. A​ 20-ounce bottle costs​ $5.60. What is the best​ buy?

• 6 oz

• 14 oz

• 20 oz

During a thunderstorm​ yesterday, 600 millimeters of rain fell in 30 minutes. What is the unit rate for millimeters per​ minute?

• .05

• 18,000

• 25

• 20

Population density is the number of people per unit of area. The population density of a certain region is 60 people per square kilometer. If the region covers 23 square​ kilometers, what is the population of the​ region?

• 1380

• 2.61

• .38

• 1285

In​ basketball, some baskets are worth two points. Others are worth three points. In one​ game, the ratio of​ three-point baskets to​ three-point tries for one team was 3 : 4. If the team scored 27 points from​ three-point baskets, how many​ three-point tries did the team​ have?

• 12

• 36

• 7

• 3

A covered bridge is 8 yards long. In a painting for sale at a​ gallery, the bridge is 5 feet long. A customer wants to know the ratio of the length of the bridge in the painting to the actual length of the bridge. One salesperson says the ratio in simplest form is 5:8. Another salesperson says the ratio in simplest form is 5:24. What error leads to the incorrect​ ratio?

• Not simplifying the terms of the ratio

• .

  Reversing the terms of the ratio

• Using terms with different units to find the ratio