Math 110 Homework 2: Ratios and Proportions Winter 2019

Name:

This is due on Tuesday, January 15 at the beginning of class. Please write your answers neatly in this packet in pencil.

1. (2 points) In a given pond, there are 22 rock fish for every 121 minnows. Express the ratio of minnows to rock fish in lowest terms.

2. (3 points) Write 6 : 11 in two other ways. Write three equivalent ratios.

3. (3 points) Sourdough bread uses a 3-to-2 ratio of flour to sourdough starter. If you have 1 cup of flour, how much sourdough starter should you use? What if you have 7 cups of flour? Give your answers as fractions or mixed number (e.g. 1 and 1/3 cups).

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Math 110 Homework 2: Ratios and Proportions Winter 2019

4. (3 points) The ratio of earthquake safe buildings to non-earthquake safe buildings in Oregon is 2

7 . If there are 350, 000 buildings in the state of Oregon, how many of them

are not earthquake safe? Make sure your answer is reasonable.

5. An artist is drawing a tree and is trying to get the scale correct. She measure that the ratio of width-to-height of the tree is 2 : 5.

(a) (2 points) If she wants to draw the tree on her paper, and make it one foot tall, how many inches wide should she draw the tree?

(b) (2 points) In actuality, the tree is 40 feet wide. How tall is it?

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Math 110 Homework 2: Ratios and Proportions Winter 2019

6. (3 points) Alicia can run 3 miles in 28 minutes. How long will it take her to run 5 miles? Give your answer as a number of hours and a number of minutes (e.g. “1 hour 20 minutes.”)

7. (4 points) You can mow 1/3 of an acre of lawn in 45 minutes. How long would it take you to mow 2 acres of lawn? Give your answer as a number of hours and a number of minutes (e.g. “1 hour 20 minutes”).

8. (3 points) In a greenhouse, there are 67 flowering plants for every 12 non-flowering plants. There are 395 total plants in the greenhouse. How many of them are flowering plants?

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Math 110 Homework 2: Ratios and Proportions Winter 2019

9. (4 points) Mark’s gross monthly income is $2300. His rent is $575, his monthly car payment is $120, his utilities cost $300 per month, his student loan payment is $63 per month, and he spends $300 per month on groceries. What is his debt-to-income ratio? Is he a good candidate for a mortgage?

10. (5 points) Elizabeth’s total cholesterol is 182 and her LDL is 128. What is her choles- terol ratio? Is she at high-risk for a heart attack? Why or why not?

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Math 110 Homework 2: Ratios and Proportions Winter 2019

11. At your job, you make $90 in 7 hours.

(a) (3 points) If you work 10.5 hours, how much money will you make? (Assume you do not make overtime.)

(b) (3 points) What is the constant of proportionality in this example, and what does it mean?

12. (4 points) 5 painters can paint 20,000 square feet in 4 hours. How long will it take 2 painters to paint the same area?

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