Correct Answer: C

Rationale: The correct answer is 7.3. To subtract 13.4 from 20.7, you align the decimal points and subtract each place value: 0.7 - 0.4 = 0.3, and 2 - 1 = 1. Therefore, 20.7 - 13.4 = 7.3. Choices A, B, and D are incorrect because they do not provide the accurate result of this subtraction.

Correct Answer: A

Rationale: To convert 0.004 to a ratio, first express it as a fraction. 0.004 = 4/1000 = 1/250. Therefore, the ratio is 1:250. Choice A is the correct answer. Choices B, C, and D are incorrect ratios as they do not represent the equivalent fraction of 0.004.

Correct Answer: C

Rationale: To find the total number of chapters, divide the total number of pages by the number of pages per chapter: 798 · 6 = 133 chapters. Reading 2 chapters per day means it will take 133 · 2 = 66.5 days. Choice A, 133 days, is incorrect because it miscalculates the days needed to finish the book. Choice B, 399 days, is incorrect as it doesn't consider the number of chapters read per day. Choice D, 75 days, is incorrect as it doesn't account for the total number of chapters in the book.

Correct Answer: D

Rationale: To convert ounces to pounds, you need to know that there are 16 ounces in a pound. Therefore, to find out how many pounds are in 144 ounces, you divide 144 by 16, which equals 9 pounds. Choice A, 12 pounds, is incorrect because it does not correctly divide the number of ounces by the conversion factor. Choices B and C, 10 pounds and 8 pounds respectively, are also incorrect as they do not utilize the correct conversion factor to calculate the number of pounds in 144 ounces.

Correct Answer: A

Rationale: To find the weight in pounds, divide the weight in grams by the conversion factor (453.59 grams per pound). 3,459 grams · 453.59 = approximately 7 lbs 10 oz. Therefore, choice A (7 lbs 10 oz) is the correct answer. Choice B (10 lbs 7 oz) and Choice C (13 lbs 3 oz) are incorrect as they do not correspond to the correct conversion. Choice D (3 lbs 13 oz) is incorrect as it does not account for the additional pounds derived from dividing 3,459 grams by the conversion factor.