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.

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: 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 the mean time, you need to add all the times (22.33 + 22.50 + 22.50 + 22.61 + 22.71 + 22.72 + 22.83 + 23.22) and then divide by the total number of times (8). This calculation results in a mean time of 22.68 seconds. Choice A, 22.50 sec, is incorrect because it is the time of one of the runners, not the mean time. Choice B, 22.66 sec, and Choice D, 22.77 sec, are also incorrect as they are not the calculated mean of the given times.

Correct Answer: B

Rationale: To find the increase in temperature after 20 minutes, calculate how many 3-minute intervals are in 20 minutes (20 · 3 = 6.66, rounding to 7 intervals). Then, multiply the temperature increase per interval (2 °C) by the number of intervals (7 intervals), giving a total increase of 14 °C. Therefore, after 20 minutes, the temperature of the water would have increased by approximately 14 °C. Choice A, 10 °C, is incorrect as it underestimates the total increase. Choice C, 15 °C, is incorrect as it overestimates the total increase. Choice D, 35 °C, is incorrect as it represents the initial temperature of the water, not the increase in temperature.