# Lesson 9

Solving Rate Problems

Let's use unit rates like a pro.

This package of sliced cheese costs $2.97. How much would a package with 18 slices cost at the same price per slice? Explain or show your reasoning. ### Problem 2 A copy machine can print 480 copies every 4 minutes. For each question, explain or show your reasoning. 1. How many copies can it print in 10 minutes? 2. A teacher printed 720 copies. How long did it take to print? ### Problem 3 Order these objects from heaviest to lightest. (Note: 1 pound = 16 ounces, 1 kilogram $$\approx$$ 2.2 pounds, and 1 ton = 2,000 pounds) item weight school bus 9 tons horse 1,100 pounds elephant 5,500 kilograms grand piano 15,840 ounces ### Problem 4 Andre sometimes mows lawns on the weekend to make extra money. Two weeks ago, he mowed a neighbor’s lawn for $$\frac{1}{2}$$ hour and earned$10. Last week, he mowed his uncle’s lawn for $$\frac{3}{2}$$ hours and earned $30. This week, he mowed the lawn of a community center for 2 hours and earned$30.

Which jobs paid better than others? Explain your reasoning.

(From Unit 3, Lesson 5.)

### Problem 5

Calculate and express your answer in decimal form.

1. $$\frac12 \boldcdot 17$$
2. $$\frac34 \boldcdot 200$$
3. $$(0.2) \boldcdot 40$$
4. $$(0.25) \boldcdot 60$$
(From Unit 3, Lesson 1.)

### Problem 6

Here is a polygon.

1. Decompose this polygon so that its area can be calculated. All measurements are in centimeters.
2. Calculate its area. Organize your work so that it can be followed by others.
(From Unit 1, Lesson 11.)