Correct Answer: B

Rationale: There are 1,000 milliliters in 1 liter. The prefix 'milli-' means one-thousandth, so when converting from liters to milliliters, you multiply by 1,000. Therefore, the correct answer is 1,000 mL. Choice A (100 mL) is incorrect as it represents one-tenth of the correct conversion. Choice C (500 mL) is incorrect as it is half of the correct conversion. Choice D (50 mL) is incorrect as it is one-twentieth of the correct conversion.

Correct Answer: A

Rationale: To find the value of x, set up the proportion 7/9 = x/63. Cross multiply to get 7*63 = 9*x. This simplifies to 441 = 9x. Divide both sides by 9 to solve for x, giving x = 49. Therefore, the correct answer is A. Choice B (x = 39), Choice C (x = 50), and Choice D (x = 59) are incorrect as they do not match the correct calculation based on the proportion set up.

Correct Answer: C

Rationale: Rationale: To find the least common multiple (LCM) of 14 and 21, we need to determine the smallest number that is a multiple of both 14 and 21. First, list the multiples of 14: 14, 28, 42, 56, 70, 84, ... Next, list the multiples of 21: 21, 42, 63, 84, ... The smallest number that appears in both lists is 42. Therefore, the LCM of 14 and 21 is 42.

Correct Answer: D

Rationale: To find the value of x in the given ratio and proportion, we can set up the equation as 15:2000=x:200. Cross multiply to get x * 2000 = 15 * 200. Simplifying this gives x = 1. Therefore, the correct answer is D, which is 1. Choice A (7), Choice B (0), and Choice C (7,777) are incorrect as they do not match the correct calculation of x.

Correct Answer: A

Rationale: To determine the amount of medication the patient should receive, divide the prescribed dose by the dose per mL in the vial. In this case, 5 mg · 2 mg/mL = 2.5 mL. Therefore, the patient should receive 2.5 mL of the medication. Choice B (2 mL) is incorrect because it does not reflect the correct calculation. Choice C (3 mL) is incorrect as it is higher than the actual amount calculated. Choice D (1 mL) is incorrect as it is lower than the actual amount calculated.