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: C

Rationale: To determine the cost of building a fence around the square lawn, first calculate the length of one side by finding the square root of the area: √62500 = 250 meters (length of one side). The perimeter of a square is four times the length of one side, so the perimeter of the lawn is 4 * 250 = 1000 meters. To find the cost of the fence, multiply the perimeter by the cost per meter: 1000 meters * $5/meter = $5000. Therefore, the correct answer is $5,000, which corresponds to choice C. Choice A ($4,000), choice B ($4,500), and choice D ($5,500) are incorrect as they do not accurately calculate the cost based on the given information.

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: B

Rationale: To find the percentage of brown horses, first calculate the total number of horses: 10 black + 6 brown + 8 two-color + 3 all white = 27 horses. Then, calculate the percentage of brown horses: (6 · 27) 100 = 22.22%, which rounds to 20%. Choice B, 20%, is the correct answer. Choice A, 15%, is incorrect as it does not reflect the accurate percentage of brown horses. Choice C, 25%, is incorrect as it overestimates the percentage of brown horses. Choice D, 30%, is incorrect as it also overestimates the percentage of brown horses.

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.