Correct Answer: B

Rationale: The correct answer is B: 3000 milliliters. There are 1,000 milliliters in a liter. Therefore, 3 liters = 3 1,000 = 3,000 milliliters. Choice A (300 milliliters) is incorrect as it represents the conversion of 0.3 liters, not 3 liters. Choice C (1500 milliliters) is incorrect as it is halfway between the correct answer and a common mistake of confusing liters with milliliters. Choice D (300 milliliters) is incorrect as it is the conversion of 0.3 liters, not 3 liters.

Correct Answer: A

Rationale: Subtract the whole numbers and then subtract the fractions: 12 - 7 4\5 = 5 1\5.

Correct Answer: A

Rationale: To find out how many minutes Kevin will take to wash 100 cars, set up a proportion: 30 cars is to 15 minutes as 100 cars is to x minutes. Cross multiplying gives 30x = 1500. Solving for x, x = 1500 / 30 = 50. Therefore, it will take Kevin 50 minutes to wash 100 cars. Choice A is correct. Choice B, C, and D are incorrect as they do not correctly calculate the time needed based on the given information.

Correct Answer: D

Rationale: To find the distance traveled, multiply the speed of 70 mph by the time of 6 hours: 70 mph 6 hours = 420 miles. Therefore, the correct answer is 420 miles. Choices A, B, and C are incorrect as they do not result from the correct calculation.

Correct Answer: A

Rationale: To calculate 54% of $789.56, you multiply 0.54 by 789.56, which equals $426.36. Therefore, choice A, $426.36, is the correct answer. Choice B, $426.37, is incorrect as it is a slightly higher value. Choice C, $363.20, is incorrect as it is significantly lower than the correct answer. Choice D, $526.38, is incorrect as it is higher than the correct calculation result.