Correct Answer: A

Rationale: The correct subtraction is 9.5 - 4.7 = 4.8. Therefore, the correct answer is 4.8. Choice B (4.9) is incorrect because 9.5 - 4.7 is not equal to 4.9. Choice C (4.6) is incorrect as it is not the result of subtracting 4.7 from 9.5. Choice D (4.7) is the number being subtracted and not the result of the subtraction.

Correct Answer: D

Rationale: The correct answer is D, 8 pounds. There are 16 ounces in a pound. To convert 128 ounces to pounds, you divide 128 by 16, which equals 8 pounds. Choice A, 16 pounds, is incorrect because that would be the conversion the other way around, from pounds to ounces. Choices B and C are incorrect as they do not reflect the correct conversion from ounces to pounds.

Correct Answer: C

Rationale: In this scenario, to find the total amount of medication administered in 3 hours, we first calculate the total drops administered by multiplying the drops per minute by the total minutes. This gives us 40 drops/minute * 180 minutes = 7200 drops. Then, we convert the drops to milligrams by multiplying the total drops by the amount of medication in each drop, which is 1mg. Therefore, 7200 drops * 1mg/drop = 7200mg. The correct answer is 7,200mg. Choice A is incorrect as it miscalculates the total amount. Choice B is incorrect as it doubles the correct answer. Choice D is incorrect as it quadruples the correct answer.

Correct Answer: D

Rationale: There are 32 ounces in a quart. Therefore, 3 quarts would be equal to 3 quarts x 32 ounces = 96 ounces. The correct answer is D. Choice A, 64 ounces, is incorrect as it miscalculates the conversion from quarts to ounces. Choice B, 32 ounces, is the conversion for 1 quart, not 3 quarts. Choice C, 48 ounces, is also an incorrect calculation, not considering the correct conversion rate.

Correct Answer: A

Rationale: To add mixed numbers, convert them to improper fractions: 6 3/4 = 27/4 and 8 1/6 = 49/6. Then, add the fractions to get 27/4 + 49/6 = 162/24 + 98/24 = 260/24 = 21 20/24 = 21 10/12 = 21 5/6 = 14 11/12. Therefore, the correct answer is 14 11/12. Choice B (12 3/4) is incorrect as it does not match the correct calculation. Choice C (12 3/24) is incorrect due to the erroneous denominator in the final fraction. Choice D (14 2/5) is incorrect as it does not correspond to the correct sum of the fractions.