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: 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: A

Rationale: The correct ratio of men to women is 3:4. To find the ratio, divide the number of men by the number of women: 12 men / 16 women = 3/4, which simplifies to 3:4. Therefore, in a class of 28 people with 12 men and 16 women, the ratio of men to women is 3:4. Choice B (4:7) is incorrect because it does not accurately reflect the given numbers of men and women in the class. Choice C (12:16) is incorrect as it represents the actual count of men and women, not the ratio. Choice D (1:2) is incorrect as it does not match the proportion of men to women in the class.

Correct Answer: C

Rationale: To find the perimeter of a shape with equal sides, you multiply the length of one side by the number of sides. In this case, the honeycomb cell has 6 sides, each measuring 8mm. Therefore, the perimeter is calculated as perimeter = number of sides * side length = 6 * 8mm = 48mm. Choices A, B, and D are incorrect because they do not correctly calculate the total length around the honeycomb cell with six sides.

Correct Answer: B

Rationale: In the metric system, there are 1000 grams in 1 kilogram. To convert kilograms to grams, you multiply the number of kilograms by 1000. Therefore, 4 kilograms would equal 4000 grams. Choice A (400 grams) is incorrect because it is the result of multiplying by 100, not 1000. Choice C (40 grams) is incorrect as it is the result of dividing by 1000 instead of multiplying. Choice D (100 grams) is incorrect as it is a random figure and not the correct conversion from kilograms to grams.