Lesson 23

Solving Percentage Problems

Let's solve more percentage problems.

Problem 1

Complete each statement.

• 20% of 60 is ________
• 25% of ________ is 6
• ________% of 100 is 14
• 50% of 90 is ________
• 10% of ________ is 7
• 30% of 70 is ________

Problem 4

1. To find 40% of 75, Priya calculates $$\frac{2}{5} \boldcdot 75$$. Does her calculation give the correct value for 40% of 75? Explain or show how you know.
2. If $$x$$ represents a number, does $$\frac{2}{5} \boldcdot x$$ always represent 40% of that number? Explain your reasoning.

Problem 5

Han spent 75 minutes practicing the piano over the weekend. For each question, explain or show your reasoning.

1. Priya practiced the violin for 152% as much time as Han practiced the piano. How long did she practice?
2. Tyler practiced the clarinet for 64% as much time as Han practiced the piano. How long did he practice?

Problem 6

An ant travels at a constant rate of 30 cm every 2 minutes.

1. At what pace does the ant travel per centimeter?
2. At what speed does the ant travel per minute?
(From Unit 2, Lesson 18.)