Consumer Math Answers

Answers from Math And You.

Lesson 1  1.1 Checkpoint

  1. $243.71  Add together all the expenses and subtract off all the payments.
  2. 88 teaspoons (worked out)  35 calories in a serving (worked out)
  3. d
  4. 16 boxes (worked out)  $1468.80  (worked out)
  5. 70 minutes  (total calories divided by calories burned per hour) (worked out)
  6. greater than  (worked out – one, two, $2304 is 4%)

Lesson 2  1.1 Exercises

  1. $47.08  (worked out)
  2. $39.41  (worked out)
  3. 1360 calories in recipe and 150 per serving (worked out – one, two, fraction/decimal help)
  4. 3810 (worked out) $310 (worked out)
  5. $40 (worked out)
  6. $806  Total cost: $834  Area  Number of 10-pound bags  Total Cost
  7. about 8 and a half minutes  (worked out)
  8. between 6.7 and 18.7 minutes  (worked out steps: one, two, three, four)
  9. 36,000 miles per hour about  (worked out with specific answer)
  10. $-21.49 (worked out) Negative means they owe you money. $80.71 a month (worked out)
  11. 13,565    Circular Base  Vertical Wall  Tiled Area  Answer in Inches
  12. One is more guaranteed income. One is more potential income.  (worked out)

Lesson 3  1.2 Checkpoint

  1. $1129  (worked out)
  2. Miles divided by gallons c. 45 m/g   d. 18 m/g
  3. Answer image
  4. 16 gigabytes  (worked out)
  5. E and F are okay. D could be: The weight of an athlete is about 215 pounds.
  6. 15 characters, This uses the average length for a first and last name. (worked out)

Lesson 4  1.2 Exercises

  1. 3,900,000,000,000 kilowatt hours
  2. about 13,000 kilowatt hours per person  (worked out)
  3. $12 a year (worked out)
  4. The difference is $140 over 7 years. Multiply each year’s cost by 7. (worked out for the current fridge)
  5. meso plankton  (worked out)
  6. femto plankton  (worked out)
  7. about 25 million (can’t know exactly)
  8. about 5 pounds
  9. area of the living room is 297 square feet, so buy 300 sq feet (worked out) and multiply by the price per square foot to get total price $1047  (worked out)
  10. $31, round each price first
  11. 220 miles (though the curvy road would be longer than that)

Lesson 5  1.3 Checkpoint

  1. 395, 218 miles squared  (worked out)
  2. 94,594,500 cats (worked out)
  3. 41%  (worked out)
  4. answers will vary
  5. answers will vary

Lesson 6 1.3 exercises

  1. 67,860,000 American men (worked out)
  2. .
  3. Add the populations and then estimate: 9,600,000 adults with no opinion (worked out)
  4. .
  5. 1,236,690 people  (worked out part 1, part 2)
  6. .
  7. skipped
  8. .
  9. 73.7%  (worked out)
  10. .
  11. 4.9%  (worked out)
  12. .
  13. 51.5%  Add the number of bones to get 106 then…  (worked out)
  14. .
  15. 18.75%  (worked out)
  16. .
  17. 0.5 carat is $971 through $2026 (worked out), 1 carat is from that through $6892 (worked out), 2 carats through $16,092 (worked out).
  18. .
  19. $14,066  (worked out part 1, part 2)
  20. .
  21. 67%  (worked out)
  22. .
  23. a) 1 b) 1 c) .5  (worked out part a, part b, part c)

Lesson 7  1.4 Checkpoints

1. $1,181,180 (worked out)

3. c) Approximately 14.6  d) 131.2 (worked out part c, part d)

5. 31,556,925,19 (worked out)

7. c) About 40s  d) About 30s

9. c) $4.24 (worked out)

11. a) 68 degrees b) 25 degrees

Lesson 8  1.4 Exercises

1. $2.45 (worked out)

3. 3-5 days = $12.47, 2 days = $23.14, savings = $10.40 (worked out 1, 2, 3)

5. 1 day $300.51, 2 days $141.51, 3-5 days $77.91 (worked out 1, 2, 3)

7. b. It will take 12 mins (worked out 1, 2)

9. 0.625 lb (worked out)

11. Approximately 5.47 qt/1 min (worked out)

13. 0.8 sec. (worked out)

15. Approximately 20,321.52 ft (worked out)

17. Approximately 10.007 ft/min (worked out)

19. 156.2 (worked out)

21. Method 1 $352.63, method 2 $352.57 The difference in the dollar amounts is due to round-off error. In either case, the cost of the product is about $352.60. (worked out 1, 2)

23. Approximately $53.98 per tank (worked out method 1, method 2)

Lesson 9  

Extending Concepts 33

25. When you lose 20% of $1250, you lose $250. Your investment is now worth only $1000. If you gain 20% during the second year, then you will have gained $200. (worked out 1, 2)

31. 92% (equation, spreadsheet 1, 2)

Extending Concepts 43

21. Approximately $352.63 with method 1, and $352.57 with method 2 Difference due to round off error. (worked out method 1, 1, 2, method 2, 1, 2)

23. Approximately $53.98 with method 1, and $53.97 with method 2. Again, the difference is due to round off error. (worked out method 1, 1, 2, method 2, 1, 2)

Part 1-2

1. b. (worked out, each step 1, 2, 3, 4, 5, 6, 7, 8 The problem with a. What b. is doing)

3. Using total area 3.4 people per km squared. Using land area (9,093,507 km squared) 3.75 people per km squared. (worked out total area, land area 1, 2)

5. Approximately 3968 people per km squared. (worked out)

Part 3-4

1. 14,040,000 people (worked out)

3. As they get older they are more likely to become disabled (U.S. Pop. by Age)

5. 60 in. (worked out)

7. 12 furlongs (worked out)

Lesson 10

1. a) Correct (worked out)

b) Not correct (worked out)

3. 3.5 hr (solution using unit analysis, here is a solution using the formula t=d/r)

5. 1875 miles, for eight years it’s 234.375 miles per year (worked out 1, 2)

7. 19,500,000 barrels of oil per day (worked out)

9. China consumed around 7,800,000, which is 0.006 barrels of oil per person per day, an d 0.252 gallons of oil per person per day. The USA consumed about 0.064 barrels of oil per person per day, and around 2.688 gallons of oil per person per day. (worked out China, 1, 2, 3, USA, 1, 2)

11. 520,000 barrels of oil per day, 189,800,00 for the entirety of 2008 (worked out 1, 2)

13. 9,975,00 cubic miles (worked out)

15. 51.6% (worked out)

17. 29,925 cubic miles of fresh surface water. If the melting of icecaps and glaciers added 6000 cubic miles to this surface water, then that would be a percent change of 20.1% (worked out 1, 2)

19. Earth’s water occurs as:

  1. Oceans
  2. Icecaps and Glaciers
  3. Ground water (wells, aquifers)
  4. Surface water (rivers, lakes, ponds, wet lands, streams)

What else is there? The answer is that water also occurs in the atmosphere and in the    bodies of plants and animals.

21. 7.83 knots (worked out)

23. 3.45 miles (worked out)

25. 30 ft (worked out)

Lesson 11

Unit Prices

1. Caviar = $106.71/oz, Wrinkle Cream = $70.00/fl oz, Honey = $1.31/1 oz (worked out 1, 2, 3)

Checkpoints

1. c) $2.15 per gallon of milk d) 41% (worked out c, d)

2. Homemade = $0.01 per load Brand B = $0.14 per load (worked out 1, 2, 3, 4)

3. Around $0.055 (worked out 1, 2)

4. $540 (worked out 1, 2, 3)

5. d) $2.75 e) $20.80 (worked out d 1, 2, e 1, 2)

Lesson 12

Exercises

1. About $0.174 (worked out)

3. About $0.05 per fluid ounce (worked out)

5. a) $0.98 b) 38.1% (worked out a, b)