Correct Answer: C

Rationale: To find the percentage of 8 in 40, divide 8 by 40 to get 0.2. Multiply this result by 100 to convert it to a percentage: 0.2 100 = 10%. Therefore, 8 is 10% of 40, making choice C the correct answer. Choices A, B, and D are incorrect percentages calculated from incorrect divisions and multiplications.

Correct Answer: C

Rationale: To find the percentage of 8 in 40, divide 8 by 40 to get 0.2. Multiply this result by 100 to convert it to a percentage: 0.2 100 = 10%. Therefore, 8 is 10% of 40, making choice C the correct answer. Choices A, B, and D are incorrect percentages calculated from incorrect divisions and multiplications.

Correct Answer: A

Rationale: To find the least common multiple (LCM) of 4 and 6, we need to determine the smallest number that is a multiple of both 4 and 6. The multiples of 4 are: 4, 8, 12, 16, 20, 24, ... The multiples of 6 are: 6, 12, 18, 24, ... The least common multiple is the smallest number that appears in both lists. In this case, the least common multiple of 4 and 6 is 12, not 24. Therefore, the correct answer is 24. Choice B (12) is actually the least common multiple of 4 and 3, not 4 and 6. Choices C (6) and D (3) are not multiples of both 4 and 6, so they are incorrect.

Correct Answer: B

Rationale: Let Mr. Johnson's pay be represented as x. After giving half of his pay to his family, he has x/2 left. Subtracting $250 paid to his landlord, he has x/2 - $250 remaining. Given that this remaining amount is 3/7 of his original pay, the equation becomes x/2 - $250 = 3x/7. Solving this equation shows that x = $3,500. Therefore, Mr. Johnson receives $3,500. Choices A, C, and D are incorrect as they do not align with the correct calculation based on the given conditions in the question.

Correct Answer: A

Rationale: The correct answer is A: 0.09%. To convert 0.0009 to a percentage, move the decimal point four places to the right and add a percentage sign. Therefore, 0.0009 is equal to 0.09%. Choice B (9%) is incorrect as it represents 0.09 without the decimal point adjustment. Choice C (0.01%) is incorrect as it represents 0.0009 with one less zero. Choice D (0.90%) is incorrect as it represents 0.9 not 0.0009.