Name: Date: CHAPTER TEST A 5 Direct and Inverse Proportion Concepts and Skills 25 Suggested Time: 30 min (Questions 1 to 6: 6 1 point 6 points, Questions 7 and 8: 2 2 points 4 points) Tell whether each table, graph, or equation represents a direct proportion, an inverse proportion, or neither. x 7 9 15 y 3.5 4.5 7.5 y 2. y 3. 4 12 3 9 2 6 1 3 0 1 4. y 4x 3 2 3 4 x 0 5. 2y 1 2 1 x 5 Find the constant of proportionality. Then write an equation relating x and y. 6. y is directly proportional to x, and y 35 when x 7. 48 x © Marshall Cavendish International (Singapore) Private Limited. 1. Chapter 5 Test A (M)MIFAss_C2_05.indd 48 6/15/12 10:07 AM Name: Date: Solve using proportional reasoning. 7. y is directly proportional to x, and y 216 when x 2. a) Find y when x 7. b) Find x when y 540. 8. r is inversely proportional to s, and s 30 when r 10. a) Write an equation relating r and s. b) Find s when r 150. © Marshall Cavendish International (Singapore) Private Limited. Problem Solving (Question 9: 2 points, Questions 10 to 12: 3 3 points 9 points, Question 13: 4 points) Use a proportion to solve each question. Show your work. 9. The circumference, C, of a circle is directly proportional to the diameter, d, of a circle. They are related by the formula C U d. a) Find the constant of proportionality in the formula. b) What is the diameter of a circle with circumference 105 centimeters? Round your answer to the nearest tenth. Use 3.14 as an approximation for U . Assessments Course 2 (M)MIFAss_C2_05.indd 49 49 6/25/12 1:38 PM Name: Date: 10. The volume of paint used, V liters, is directly proportional to the area, A square feet, that the paint can cover. 5 liters of paint can cover a wall with an area of 75 square feet. a) Find the constant of proportionality. b) Write an equation relating V and A. c) How much paint would be needed to cover an area of 180 square feet? 11. Jane paints clay figurines to sell at a crafts fair. The graph shows that the number of figurines she paints, y, is directly proportional to the number of days she paints, x. y 30 25 20 15 10 5 0 1 2 3 4 5 6 x Number of Days 50 a) Find the constant of proportionality. b) What does the constant of proportionality represent in this situation? c) How long will it take Jane to paint 30 figurines? © Marshall Cavendish International (Singapore) Private Limited. Number of Clay Figurines Painting Clay Figurines Chapter 5 Test A (M)MIFAss_C2_05.indd 50 6/15/12 10:07 AM Name: Date: 12. The table shows the daily houseboat rental rate, in P dollars, for x number of people. Number of People (x) Rental Rate (P dollars per person) 1 2 3 240 120 80 a) Describe the relationship between the number of people and the daily houseboat rental rate. b) Write an equation relating x and P. c) What is the rental rate, in dollars per person, if 6 people plan to rent the houseboat? © Marshall Cavendish International (Singapore) Private Limited. 13. The time taken to cycle a particular distance varies inversely with the speed of the bicycle. Tim takes 3 hours to reach his destination traveling at a constant speed of 12 miles per hour. a) Find the constant of proportionality. b) What does the constant of proportionality represent in the context of the problem? c) Write an equation relating speed and time. d) How long would it take Tim to reach his destination if he travels at a constant speed of 15 miles per hour? Assessments Course 2 (M)MIFAss_C2_05.indd 51 51 6/15/12 10:07 AM Name: Date: CHAPTER TEST B 5 Direct and Inverse Proportion Concepts and Skills 25 Suggested Time: 30 min (Questions 1 to 6: 6 1 point 6 points, Questions 7 and 8: 2 2 points 4 points) Tell whether each table, graph, or equation represents a direct proportion, an inverse proportion, or neither. 1. x 2 y 15 4 7 1 2 8 3 3 4 y 2. 4 3 2 1 1 2 3 x 4 3. xy 18 4. y 2.25x Find the constant of proportionality for each situation. Then write an equation relating x and y. 5. x is inversely proportional to y, and x 9 when y 4. 6. y is directly proportional to x in the table shown below. 52 x 2 y 5 3 7 1 2 5 12 © Marshall Cavendish International (Singapore) Private Limited. 0 1 2 Chapter 5 Test B (M)MIFAss_C2_05.indd 52 6/15/12 10:07 AM Name: Date: Solve using proportional reasoning. 7. p is directly proportional to m, and p 128 when m 8. a) Find p when m 10. b) Find m when p 80. 8. x is inversely proportional to y, and x 18 when y 4. a) Write an equation relating x and y. b) Find x when y 30. Problem Solving (5 3 points 15 points) © Marshall Cavendish International (Singapore) Private Limited. Use a proportion to solve each question. Show your work. 9. The cost of a piece of ribbon, c, is directly proportional to the length of the ribbon, r. The cost of 8 meters of ribbon is $5.60. a) Find the cost per meter of the ribbon. b) Write an equation relating c and r. c) Find the value of c when r is 9. Assessments Course 2 (M)MIFAss_C2_05.indd 53 53 6/15/12 10:07 AM Name: Date: 10. The table below shows the relationship between mass in grams and mass in ounces. The mass in grams is directly proportional to the mass in ounces. Mass (x ounces) 2 4 6 Mass (y grams) 56.7 113.4 170.1 a) Find the constant of proportionality. b) Write a direct proportion equation. c) How many grams are in 7 ounces? 54 a) Find the constant of proportionality. b) Write an equation relating N and M. c) Find the value of M when N 5. © Marshall Cavendish International (Singapore) Private Limited. 11. M varies inversely as N, and M 60 when N 2. Chapter 5 Test B (M)MIFAss_C2_05.indd 54 6/15/12 10:07 AM Name: Date: 12. The graph below shows the exchange rate between U.S. dollars (USD) and Thailand baht (THB). y Currency Exchange Rates 210 Thailand Baht 180 150 120 90 60 30 0 1 2 3 4 5 6 7 x © Marshall Cavendish International (Singapore) Private Limited. U.S. Dollars a) What is the exchange rate when you convert U.S. dollars to Thailand baht? b) Sam wants to exchange 120 Thailand baht for U.S. dollars. Find the amount of U.S. dollars he will receive. c) Dave wishes to exchange 7 U.S. dollars for Thailand baht. Find the amount of Thailand baht he will receive. 13. The number of students, n, is inversely proportional to the time, t days, required to complete a project. It takes 12 students 20 days to complete a project. a) Find the constant of proportionality. b) Write an inverse proportion equation. c) Find the number of days it would take for 15 students to complete the same project. Assessments Course 2 (M)MIFAss_C2_05.indd 55 55 6/15/12 10:07 AM 10. 5. q 1 1 4 0 1 2 3 1 3 4 11. 2 1 7 6 5 4 3 14 15 16 17 18 1 1 3 0 1 6. x f 2 12. 13. 15. 17. 19. 21. 23. 25. 14. 16. 18. 20. 22. 24. x ≤ 50,000 x ≤ 300 x ≥ 18 x 150 x ≤ 2,000 x ≥ 45 x 10 x 95 x 500 1. x 4 3. r 5 2. m 20 4. a 2 1 2 4 3 2 1 1 7. y 3 2 3 3 1 2 4 5 6 8. p f 5 8 Chapter 4 Test A 5. y f 5 9. 11. 12. 13. 14. 7 6 5 4 39 in. 10. $6 b 41 51 bags of popcorn At least 22 points At least 4 computers Chapter 5 Pre-Test 4 6. x © Marshall Cavendish International (Singapore) Private Limited. 2 1 2 1 0 1 2 0 3 4 3 7. y v 3 3 41 1 2 0 1 2 1 2 3 4 1 2 3 4 8. x 1 0 9. 11. 13. 14. $0.55 10. 45 people x 32 12. At least 97 At most 33 students x 30 1. 3. 5. 7. 8. 4:5 2. Yes 4. No 6. Yes; Sample: 14 : 30; 21 No; Sample: 3 : 9; 1 : 3 5:8 Yes No : 45 22 33 ; 24 36 10 15 10. Yes; Sample: ; 18 27 9. Yes; Sample: 11. 5.7 m/s 12. A: $0.26/fl oz; B: $0.23/fl oz; B is the better buy. 13. A: $1.07 per oz; B: $1.06 per oz; B is the better buy. 14. A(4, 3); B(3, 4); C(1, 2); D(5, 1) 15. 780 girls 16. $21.25 Chapter 5 Test A Chapter 4 Test B 1. m 3 3. y 40 2. x 2 4. p 6 1. 2. 3. 4. Direct proportion Neither Inverse proportion Neither Assessments Course 2 (M)MIFAss_C2_ANS.indd 179 179 6/15/12 10:15 AM U, 9. a) b) 22 or 3.14 7 33.4 cm 1 15 10. a) V b) c) 11. a) b) 1 A 15 12 L 5 It represents the number of clay figurines she paints per day. 6 days The value of x increases as the value of P decreases, and the product of x and P is a constant value. Hence, the rental rate is inversely proportional to the number of people renting the houseboat. xP 240 $40 36 It represents the distance traveled. st 36 2.4 h c) 12. a) b) c) 13. a) b) c) d) Chapter 5 Test B 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 180 Inverse proportion Neither Inverse proportion Direct proportion 36; xy 36 2.5; y 2.5x a) p 160 b) m 5 a) xy 72 b) x 2.4 a) $0.70 b) c 0.7r c) c 6.3 a) 28.35 b) y 28.35x c) 198.45 g a) 120 b) NM 120 c) M 24 12. a) b) c) 13. a) b) c) 30 Thailand baht per U.S. dollar 4 USD 210 THB 240 nt 240 16 days Mid-Course Test A 1. 3. 5. 7. 9. 11. 12. 13. 14. 15. B D C B D 2,100 mi 0.55p 12q yv6 x1 11x 2. 4. 6. 8. 10. C B B A A 4 5 16. 3 p 17. U4 4, 871 32.4 63 23 8 25 18. 12°F 19. a) 3,240 ft b) 194,400 ft 20. $(2.4x 0.45y 2.2) 21. 190 22. x 6 23. a) One floor above ground level b) $270 24. a) 1 3 x (168 − x ) 76 8 4 b) c) 25. a) b) c) d) e) 26. a) 80 g 8g Direct proportion 3; The cost of 1 pen is $3. y 3x It means the cost of 4 pens is $12. 8 pens i) Mount Whitney, California ii) Death Valley, California b) 6,317 ft c) Death Valley, California d) Houston, Texas 27. 13 nickel coins 28. a) (258 2.1v) mi b) 132 mi 29. 7 © Marshall Cavendish International (Singapore) Private Limited. 5. Direct proportion 6. 5; y 5x 7. a) y 756 b) x 5 8. a) sr 300 b) s 2 Answers (M)MIFAss_C2_ANS.indd 180 6/15/12 10:15 AM