Correct Answer: D

Rationale: To find 70% of a number, you multiply the number by 0.70. Therefore, 70% of 200 is calculated as 0.7 200 = 140. Choices A, B, and C are incorrect as they do not represent the correct calculation for finding 70% of 200.

Correct Answer: A

Rationale: 300 milliliters is equivalent to 0.3 liters. To convert milliliters to liters, you need to move the decimal three places to the left. Therefore, the correct answer is A. Choice B (3 liters) is incorrect as it represents the conversion of 3000 milliliters. Choice C (0.03 liters) is incorrect as it represents the conversion of 30 milliliters. Choice D (3.3 liters) is also incorrect as it is not the correct conversion of 300 milliliters.

Correct Answer: A

Rationale: To subtract mixed numbers, first subtract the fractions: 1/8 - 1/2 = -3/8. Then, subtract the whole numbers: 12 - 9 = 3. Combine the whole number and fraction: 3 - 3/8 = 2 5/8. Therefore, the correct answer is A. Choice B is incorrect because it does not reflect the correct subtraction of the fractions. Choices C and D are incorrect as they do not result from the correct subtraction process outlined above.

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: D

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. If he reads 2 chapters a day, it will take him 133 · 2 = 66.5 days to finish the book. Therefore, the correct answer is 66.5 days. Choice A is incorrect because it miscalculates the number of days required. Choices B and C are incorrect as they do not consider the correct calculation based on the given information.