Correct Answer: A

Rationale: To convert 5/8 to a decimal, divide 5 by 8: 5 · 8 = 0.625. The correct answer is A (0.625). Choice B (0.5) is incorrect because it represents 1/2. Choice C (0.4) is incorrect because it represents 2/5. Choice D (0.75) is incorrect because it represents 3/4.

Correct Answer: B

Rationale: To convert a fraction to a decimal, divide the numerator by the denominator. In this case, 1 · 5 = 0.2. Therefore, the correct answer is B. Choice A (0.5) is incorrect because the decimal form of 1/5 is not 0.5. Choice C (1.5) is incorrect as it is the sum of 1 and 0.5, not the decimal form of 1/5. Choice D (0.15) is incorrect as it is the decimal form of 15/100, not 1/5.

Correct Answer: D

Rationale: The correct answer is D, 60. To find 50% of 120, you multiply 0.5 by 120: 0.5 x 120 = 60. Choice A and B are incorrect as they are duplicates. Choice C, 70, is incorrect because it is not the result of calculating 50% of 120.

Correct Answer: A

Rationale: The correct answer is A: 10 pounds. There are 16 ounces in a pound. To convert 160 ounces to pounds, you need to divide 160 by 16, which equals 10 pounds. Choice B, 8 pounds, is incorrect because it does not account for the correct conversion factor. Choice C, 5 pounds, is incorrect as it is not the result of dividing 160 by 16. Choice D, 12 pounds, is incorrect as it overestimates the conversion.

Correct Answer: A

Rationale: The correct subtraction is 12.02 - 9.99 = 2.03. Therefore, the correct answer is A. Choice B, 2.21, is incorrect as it does not result from the given subtraction. Choice C, 3.17, is also incorrect. Choice D, 7.97, is incorrect as well. Thus, A is the only correct answer.