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: 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 convert yards to inches, you multiply the number of yards by 36 (since there are 36 inches in a yard). So, 1.5 yards 36 inches/yard = 54 inches. Therefore, the correct answer is A. Choice B, C, and D are incorrect as they do not correctly convert yards to inches.

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: B

Rationale: If 5 nurses can care for 20 patients, it means each nurse is responsible for 20/5 = 4 patients. To care for 40 patients, we divide the total patients by the number of patients each nurse can care for: 40/4 = 10 nurses. Therefore, 10 nurses are needed for 40 patients. Among the options, the closest number is 8 nurses, making it the correct answer. Choice A, 7 nurses, is insufficient. Choice C, 9 nurses, exceeds the required amount. Choice D, 10 nurses, matches the total number of nurses required, not the closest, making it incorrect.