Correct Answer: A

Rationale: To find the percentage of Dr. Lee's patients hospitalized after taking the antibiotic, we need to calculate 30% of 5%. First, convert 30% and 5% to decimals: 30% = 0.30 and 5% = 0.05. Multiply 0.30 by 0.05 to get 0.015. To convert 0.015 to a percentage, multiply by 100, resulting in 1.5%. Therefore, only 1.50% of Dr. Lee's patients were hospitalized after taking the antibiotic. Choice A is correct. Choice B (5%) is incorrect as it represents the percentage of patients who developed an infection and not those hospitalized. Choices C (15%) and D (30%) are also incorrect percentages as they do not accurately reflect the proportion of hospitalized patients in this scenario.

Correct Answer: D

Rationale: Chan has used 30% + 30% + 25% = 85% of his bonus, which leaves 15% remaining. Since 15% of his bonus is $600, you can find the total bonus amount by dividing $600 by 15% (or multiplying by 100/15), which equals $4,000. Therefore, the correct answer is $4,000. The other choices are incorrect because they do not accurately represent the total remaining amount after the specified deductions.

Correct Answer: B

Rationale: To find the median, we first need to arrange the scores in ascending order: 81, 87, 89, 92, 94. Since there are five scores, the middle score would be the third one, which is 89. Hence, the median of Pernell's scores is 89. Choice A (87) is incorrect because it is the second score in the ordered list, not the middle one. Choice C (92) and Choice D (94) are also incorrect as they are not positioned in the middle of the ordered series.

Correct Answer: C

Rationale: To find how many hairs were used for the drug test, you need to calculate 1/7 of 100. 1/7 of 100 is 14.2857, which rounds to 14.29 when rounded to the nearest hundredth. Therefore, 14.29 hairs were used for the drug test. Choice A is incorrect as it does not account for rounding to the nearest hundredth. Choices B and D are incorrect as they do not accurately reflect the calculated value after rounding.

Correct Answer: A

Rationale: To find the volume of the aquarium, we multiply its length, width, and height. The formula for the volume of a rectangular solid is V = l w h. Substituting the given dimensions, we get V = 30 10 12 = 3600 cubic inches. Therefore, the aquarium can hold 3600 cubic inches of water. Choice B (52 cubic inches), Choice C (312 cubic inches), and Choice D (1144 cubic inches) are incorrect as they do not correctly calculate the volume of the aquarium based on its dimensions.