Lesson 20: Practice Problems

Problem 1

Solve each problem. If you get stuck, consider using the double number lines.

  1. During a basketball practice, Mai attempted 40 free throws and was successful on 25% of them. How many successful free throws did she make?

    A double number line with 7 evenly spaced tick marks. The top number line is labeled “free throws” and the first tick mark is labeled 0. The other tick marks are unlabeled. The bottom number line is not labeled and starting with the first tick mark 0, 25 percent, 50 percent, 75 percent, 100 percent, 125 percent, and 150 percent are labeled.

  2. Yesterday, Priya successfully made 12 free throws. Today, she made 150% as many. How many successful free throws did Priya make today?

    A double number line with 7 evenly spaced tick marks. The top number line is labeled “free throws” and the first tick mark is labeled 0. The other tick marks are unlabeled. The bottom number line is not labeled and starting with the first tick mark 0, 25 percent, 50 percent, 75 percent, 100 percent, 125 percent, and 150 percent are labeled.

Problem 2

A 16-ounce bottle of orange juice says it contains 200 milligrams of vitamin C, which is 250% of the daily recommended allowance of vitamin C for adults. What is 100% of the daily recommended allowance of vitamin C for adults?

A double number line with 6 evenly spaced tick marks. The top number line is labeled “vitamin C, in milligrams” and the first tick mark is labeled 0. The other tick marks are unlabeled. The bottom number line is not labeled and starting with the first tick mark 0, 50 percent, 100 percent, 150 percent, 200 percent, and 250 percent are labeled.

Problem 3

At a school, 40% of the sixth-grade students said that hip-hop is their favorite kind of music. If 100 sixth-grade students prefer hip hop music, how many sixth-grade students are at the school? Explain or show your reasoning.

Problem 4 From Unit 2 Lesson 19

Diego has a skateboard, scooter, bike, and go-cart. He wants to know which vehicle is the fastest. A friend records how far Diego travels on each vehicle in 5 seconds. For each vehicle, Diego travels as fast as he can along a straight, level path.

vehicle

distance traveled

skateboard

90 feet

scooter

1,020 inches

bike

4,800 centimeters

go-cart

0.03 kilometers

  1. 100 inches equal 254 centimeters. What is the distance each vehicle traveled in centimeters?

  2. Rank the vehicles in order from fastest to slowest.

Problem 5 From Unit 2 Lesson 18

It takes 10 pounds of potatoes to make 15 pounds of mashed potatoes. At this rate:

  1. How many pounds of mashed potatoes can they make with 15 pounds of potatoes?

  2. How many pounds of potatoes are needed to make 50 pounds of mashed potatoes?