A man is reading a book with 798 pages. If he reads 2 chapters a day and each chapter has 6 pages, how many days will it take him to finish the book?

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: 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 metric system is based on powers of 10, making calculations and conversions easier because each unit increases or decreases by a factor of 10. This factor allows for a simple and consistent way to move between different units within the system. Choice A, 'The length of Napoleon's forearm' is incorrect as the metric system is not based on a physical attribute but on a standardized mathematical factor. Choice B, '2,' and Choice D, 'Atomic weight of helium,' are also incorrect as they do not align with the foundational principle of the metric system being based on powers of 10.

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.

Correct Answer: C

Rationale: To convert gallons to ounces, we need to know that 1 gallon is equal to 128 ounces. Therefore, 2.5 gallons would be 2.5 x 128 = 320 ounces. This makes choice C, '320 ounces,' the correct answer. Choices A, B, and D are incorrect because they do not correctly calculate the conversion from gallons to ounces.

Correct Answer: B

Rationale: Rationale: - Given that the table top has dimensions of 75cm by 50cm. - Since opposite sides are equal, the table top can be divided into two pairs of equal sides: 75cm and 50cm. - To find the perimeter, we add up all four sides: 75cm + 50cm + 75cm + 50cm = 250cm. - However, since opposite sides are equal, we only need to consider two sides: 75cm + 50cm = 125cm. - Therefore, the perimeter of the table top is 125cm + 125cm = 150cm. - Hence, the correct answer is B) 150cm.

Correct Answer: B

Rationale: To find the sum of 1/3, 1/4, and 1/6, we need to first find a common denominator. The least common multiple of 3, 4, and 6 is 12. So, we rewrite the fractions with the common denominator: 1/3 = 4/12, 1/4 = 3/12, and 1/6 = 2/12. Adding these fractions together gives us 4/12 + 3/12 + 2/12 = 9/12, which simplifies to 3/4 or 1/2. Therefore, the correct answer is 1/2. Choice A (5/12) is incorrect because it does not represent the sum of the fractions given. Choices C (1/3) and D (1/4) are also incorrect as they are individual fractions and do not represent the sum of the fractions provided.

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: C

Rationale: To solve for x, cross-multiply: x/250 = 3/500. This simplifies to x = 1.5. Therefore, the correct answer is 1.5. Choice A (150) is incorrect because it does not account for the division by 250. Choice B (25.5) is incorrect as it is not the correct result of the calculation. Choice D (60) is incorrect as it is not the correct result of the calculation either.