Correct Answer: D

Rationale: The difference between the original price ($200) and the new price ($150) is $50. To find the percentage decrease, divide the difference by the original price and multiply by 100: ($50 / $200) 100 = 25%. Therefore, the correct answer is D, meaning the price decreased by 25%. Choices A, B, and C are incorrect as they do not accurately represent the percentage decrease in price.

Correct Answer: A

Rationale: To multiply decimals, align the numbers as whole numbers, multiply as if they were whole numbers, then adjust the decimal point in the final answer. When multiplying 0.67 by 0.09, the result is 0.0603. To get this result, multiply 67 by 9 to get 603, then adjust the decimal point two places to the left in the final product, resulting in 0.0603. Choice B, 0.6, is incorrect because it does not account for the decimal precision in the multiplication. Choice C, 0.603, is incorrect as it has the digits reversed when compared to the correct answer. Choice D, 0.06, is incorrect as it does not reflect the correct product of the two decimals being multiplied.

Correct Answer: A

Rationale: The correct answer is 0°C. The freezing point of water is 0°C under standard conditions. Water freezes at 0°C and boils at 100°C. Choices B, C, and D are incorrect because they do not represent the freezing point of water. 100°C is the boiling point of water, 50°C and 25°C are not related to the freezing point of water.

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: 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.