Correct Answer: B

Rationale: To find the sum of fractions with the same denominator, add the numerators. Here, 3/7 + 4/7 + 2/7 = (3 + 4 + 2)/7 = 9/7. Therefore, the correct answer is 9/7. Choice A (7/7) is incorrect as the sum is not 7/7. Choice C (6/7) is incorrect as the sum is not 6/7. Choice D (7/7) is incorrect as the sum is not 7/7.

Correct Answer: A

Rationale: To convert grams to kilograms, divide by 1,000 because there are 1,000 grams in a kilogram. Therefore, 4,000 grams · 1,000 = 4 kilograms. Choice A is correct as it represents the correct conversion. Choice B, 5 kilograms, is incorrect because it is not the result of dividing 4,000 grams by 1,000. Choice C, 1 kilogram, is incorrect because 4,000 grams is more than 1 kilogram. Choice D, 2 kilograms, is incorrect as it is not the correct conversion from grams to kilograms.

Correct Answer: D

Rationale: To convert quarts to ounces, you need to know that 1 quart is equal to 32 ounces. Therefore, to find out how many ounces are in 2.5 quarts, you multiply 2.5 by 32, which equals 80 ounces. So, the correct answer is 80 ounces. Choice A (64 ounces) is incorrect as it miscalculates the conversion. Choice B (40 ounces) is incorrect as it does not consider the correct conversion factor. Choice C (32 ounces) is incorrect as it provides the conversion for 1 quart only, not for 2.5 quarts.

Correct Answer: C

Rationale: To convert ounces to pounds, divide the number of ounces by 16 since there are 16 ounces in a pound. Therefore, 192 ounces · 16 = 12 pounds. Choice A, 16 pounds, is incorrect because it does not represent the correct conversion from ounces to pounds. Choice B, 10 pounds, is incorrect as it is not the result of dividing 192 ounces by 16. Choice D, 16 pounds, is the same as choice A and is incorrect in the context of this conversion.

Correct Answer: A

Rationale: To subtract mixed numbers, find a common denominator. Converting 6 1/2 to 6 3/6 and 2 2/3 to 2 4/6, the calculation becomes 6 3/6 - 2 4/6 = 4 1/6. Therefore, the correct answer is A. Choice B (3 1/3) is incorrect as the correct result is not an improper fraction. Choice C (3 5/6) is incorrect as it does not represent the result of the subtraction. Choice D (4 1/3) is incorrect as it does not match the correct calculation.