Correct Answer: C

Rationale: Out of all the patients who took the antibiotic, 30% developed an infection. Among those with infections, 5% required hospitalization. To find the percentage of all patients hospitalized, we multiply the two percentages: 30% * 5% = 1.5%. Therefore, 1.5% of all patients were hospitalized. Choice A (1.50%) is the calculated percentage of all patients hospitalized, not 1.50%. Choice B (5%) is the percentage of patients who developed an infection and required hospitalization, not all patients. Choice D (30%) represents the initial percentage of patients who developed an infection, not the percentage hospitalized.

Correct Answer: B

Rationale: To solve the equation 3(2y+50)−4y=500, first distribute to get 6y+150−4y=500. Combining like terms results in 2y + 150 = 500. By subtracting 150 from both sides, we get 2y = 350. Dividing by 2 gives y = 175. Therefore, the correct answer is B. Choices A, C, and D are incorrect because they do not correctly follow the steps of distributing, combining like terms, and isolating the variable to solve for y.

Correct Answer: B

Rationale: If 1 inch on the map represents 60 ft, then for 10 inches on the map, the actual distance would be 10 inches x 60 ft = 600 ft. To convert this to yards, we know that 1 yard equals 3 feet. Therefore, the distance between the two points is 600 ft / 3 ft/yard = 200 yards. Choice A (1800) is incorrect because it incorrectly multiplies by 10 again instead of converting to yards. Choice C (200) is incorrect because it fails to adjust the measurement from feet to yards. Choice D (2) is incorrect as it does not consider the correct conversion factor from feet to yards.

Correct Answer: B

Rationale: The correct order from largest to smallest number of doctors in each group is Group Z (20 doctors), Group Y (15 doctors), and Group X (10 doctors). Therefore, the correct order is Group Z, Group Y, and Group X, which matches option B. Option B is correct because it correctly reflects the descending order of the number of doctors in each group. Options A, C, and D are incorrect as they do not follow the correct order of the number of doctors in each group.

Correct Answer: C

Rationale: To determine how many prizes should be awarded to 5th-grade students, we need to set up the proportion of the number of 5th-grade students to the total number of students in the school. The total number of students is 35 + 38 + 38 + 33 + 36 = 180 students. To find the proportion of 5th-grade students, it would be 36/180 = 0.2. Since there are 20 prizes to be awarded, multiplying 0.2 by 20 gives us 4, which means 4 prizes should go to the 5th-grade students. Therefore, the correct answer is 4. Choice A (5) is incorrect as it does not align with the proportional distribution. Choice B (4) is the correct answer, as calculated. Choice C (7) is incorrect as it exceeds the total number of prizes available. Choice D (3) is incorrect as it does not match the proportional distribution based on the number of students.