Correct Answer: D

Rationale: To convert milligrams to micrograms, you need to multiply by 1000, not 10000. Therefore, to convert 0.075 mg to mcg, you multiply 0.075 by 1000, giving you 75 mcg. The correct answer is not provided in the choices, and the correct conversion is 75 mcg, which is not listed as an option. Choices A, B, and C are incorrect because they do not reflect the correct conversion factor. Choice D, 750 mcg, is a common mistake made by incorrectly adding a zero. It is important to remember that the conversion from milligrams to micrograms involves multiplying by 1000, not adding extra zeros.

Correct Answer: A

Rationale: To convert 0.004 to a ratio, we first express it as 4/1000, which simplifies to 1/250. Hence, 0.004 is equivalent to the simplified ratio of 1:250. Choice B, 4:35, is incorrect as it does not reflect the correct conversion. Choice C, 7:28, is incorrect because it does not represent the simplified ratio of 0.004. Choice D, 4:00, is incorrect as it does not simplify to the original decimal value.

Correct Answer: A

Rationale: To convert 0.3 to a fraction, we take 0.3 and express it as 3/10. This fraction is already in its simplest form because 3 and 10 do not have any common factors other than 1. Choice B, 1/3, is incorrect as it represents a different value. Choice C, 1/4, and Choice D, 1/5, are also incorrect as they do not match the equivalent fraction for 0.3.

Correct Answer: A

Rationale: To convert 0.004 to a ratio, we can express it as 4/1000, which simplifies to 1/250. Therefore, the correct ratio is 1:250. Choice B (4:200) is incorrect as it simplifies to 1:50, not 1:250. Choice C (2:400) simplifies to 1:200, which is also incorrect. Choice D (9:200) simplifies to a ratio greater than 1:1, which is not equivalent to 1:250.

Correct Answer: C

Rationale: To convert liters to milliliters, you need to multiply by 1000 since there are 1000 milliliters in 1 liter. Therefore, 3.75 liters x 1000 = 3750 milliliters. This means that option C, 3750 ml, is the correct conversion. Choices A, B, and D are incorrect because they do not reflect the correct conversion from liters to milliliters.