A rancher has a herd of different-colored horses in his corral. Ten of the horses are black, six are brown, eight are two-color horses, and three are all white. What percentage of the horses are brown? (Round to the nearest whole number if necessary).

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: 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.

Correct Answer: B

Rationale: To earn the same amount that Tim makes in 4 hours, Tim earns $30 per hour, totaling $120 in 4 hours. Joe earns $20 per hour, so to match Tim's earnings in 4 hours, Joe must work 2 hours more than Tim. Therefore, Joe needs to work 2 hours more than Tim to earn the same amount that Tim makes in 4 hours. Choices A, C, and D are incorrect as they do not accurately reflect the additional hours Joe needs to work compared to Tim to earn the same amount in 4 hours.

Correct Answer: A

Rationale: When multiplying decimal numbers like 44.44 and 55.55, align them properly and multiply each place accurately. To find the product of 44.44 and 55.55, you get 2,468.64. Therefore, the correct answer is choice A, 2,468.64. Choice B, 2,500.00, is incorrect as it is the result of rounding up. Choice C, 2,450.45, is incorrect as it is not the result of multiplying 44.44 by 55.55. Choice D, 2,470.00, is incorrect as it is not the correct product of 44.44 and 55.55.

Correct Answer: C

Rationale: To find the volume required, divide the prescribed dose (60 mg) by the concentration available (80 mg/mL): 60 mg · 80 mg/mL = 0.75 mL. Therefore, 0.75 mL is the correct amount to administer. Choice A (1 ml) is incorrect as it does not consider the concentration of the solution. Choice B (0.5 ml) is incorrect as it is half the correct amount. Choice D (1.25 ml) is incorrect as it is more than the calculated correct amount.

Correct Answer: C

Rationale: To convert 5 3/4 to a decimal, divide the numerator (3) by the denominator (4) to get 0.75. Adding this to the whole number 5 results in 5.75. When rounding to the nearest tenth, 5.75 rounds to 5.8. Therefore, the correct answer is 5.8. Choice A, 5.75, is the result before rounding to the nearest tenth. Choice B, 5.7, is incorrect as it does not account for the 0.05 difference when rounding. Choice D, 6, is the next whole number and is not the correct decimal equivalent of 5 3/4.

Correct Answer: C

Rationale: To determine the number of trees, reduce the field dimensions by 10 meters (5 meters of space on each side). The effective area is 640 meters 770 meters. Each tree occupies 10 meters 10 meters. Dividing the effective area by the space for each tree gives: (640 770) · (10 10) = 286 trees. Choice A, B, and D are incorrect because they do not consider the reduction in field dimensions and the space required for each tree.

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: Calculate the increase in dosage: 100mg * 20% = 100mg * 0.20 = 20mg. Add the increase to the original dosage to find the new dosage: 100mg + 20mg = 120mg. Therefore, the new dosage is 120mg after a 20% increase from the original 100mg dosage. Choice A (80mg) is incorrect because it represents a decrease rather than an increase. Choice B (100mg) is the original dosage and does not account for the 20% increase. Choice D (140mg) is incorrect as it is the original dosage plus 40%, not the 20% increase specified.