What percentage of her income is left after Mary spent 15%?

Correct Answer: B

Rationale: To determine the percentage of income remaining after spending 15%, subtract the percentage spent from 100% (100% - 15% = 85%). Therefore, Mary has 85% of her income left, which aligns with answer choice B. Choice A (12%) is incorrect because it represents the remaining amount after spending 88% of her income. Choice C (75%) is incorrect as it does not account for the 15% already spent. Choice D (95%) is incorrect as it does not consider the amount spent by Mary.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: The correct answer is A: 3000 meters. To convert kilometers to meters, you need to know that there are 1000 meters in 1 kilometer. Therefore, to find the number of meters in 3 kilometers, you multiply 3 by 1000, resulting in 3000 meters. Choice B, 2000 meters, is incorrect as it doesn't account for the correct conversion factor. Choice C, 3500 meters, and Choice D, 2500 meters, are also incorrect as they provide inaccurate conversions.

Correct Answer: C

Rationale: To convert grams to milligrams, you need to multiply by 1000 since there are 1000 milligrams in a gram. So, to convert 63 grams to milligrams, you would calculate 63 * 1000 = 63,000 milligrams. Therefore, the correct answer is 63,000 mg. Choice A (630 mg) is incorrect as it would be the converted value if the original amount was 0.63 grams. Choice B (63 mg) is incorrect as it is the same value as the original grams. Choice D (63,000 mg) is incorrect as it is the same as the correct answer, but with a comma which is not standard when expressing numerical values.

Correct Answer: C

Rationale: In Roman numerals, XL represents 40, and IV represents 4. When XL (40) is combined with IV (4), it forms XLIV, which corresponds to the number 44. Therefore, the correct answer is 44. Choice A (34) is incorrect as it does not consider the value of XL and IV. Choice B (54) is incorrect as it miscalculates the value of XL. Choice D (24) is incorrect as it does not account for the value of XL.

Correct Answer: B

Rationale: To determine the percentage of income remaining after spending 15%, subtract the percentage spent from 100% (100% - 15% = 85%). Therefore, Mary has 85% of her income left, which aligns with answer choice B. Choice A (12%) is incorrect because it represents the remaining amount after spending 88% of her income. Choice C (75%) is incorrect as it does not account for the 15% already spent. Choice D (95%) is incorrect as it does not consider the amount spent by Mary.

Correct Answer: A

Rationale: The correct answer is A: 28. To find 28% of 100, you multiply 0.28 (the decimal equivalent of 28%) by 100. This calculation results in 28. Therefore, 28% of 100 is 28. Choice B, 20, is incorrect as it represents 20% of 100. Choice C, 25, is incorrect as it represents 25% of 100. Choice D, 30, is incorrect as it represents 30% of 100.

Correct Answer: D

Rationale: To plant 65,536 trees with the same number of rows and trees in each row, you need to calculate the square root of 65,536. The square root of 65,536 is 256. Therefore, planting 256 trees in each row would result in 256 rows with 256 trees in each row, totaling 65,536 trees. Choices A, B, and C are incorrect as they do not provide the correct calculation based on the requirements of 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.