Correct Answer: B

Rationale: To calculate speed, divide the distance traveled by the time taken: 240 miles · 4 hours = 60 mph. Therefore, the correct answer is B. Choice A (50 mph) is incorrect as it results from an incorrect calculation. Choice C (55 mph) and D (75 mph) are also incorrect because they are not the correct result of dividing 240 miles by 4 hours.

Correct Answer: A

Rationale: 32 · (8\9) is the same as 32 (9\8) = 36.

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: B

Rationale: The correct factor to convert pounds to kilograms is 2.2. To perform the conversion, you need to divide the number of pounds by 2.2. Choice A (1.8) is incorrect as it's not the standard conversion factor. Choice C (2.5) and Choice D (2) are also incorrect factors for converting pounds to kilograms.

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.