Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply the number of liters by 1000 because there are 1000 milliliters in 1 liter. Therefore, 0.5 liters converts to 500 milliliters. Choice A (50 ml) is incorrect as it is the result of multiplying by 10 instead of 1000. Choice C (5 ml) is incorrect as it is the result of dividing by 10 instead of multiplying by 1000. Choice D (0.5 ml) is incorrect as it represents the original quantity in milliliters, not the conversion from liters.

Correct Answer: C

Rationale: To convert liters to milliliters, you need to multiply the number of liters by 1,000 because there are 1,000 milliliters in a liter. Therefore, 0.1 liter is equal to 100 milliliters. Choice A (1 ml) is incorrect because it represents the conversion of 0.01 liters, not 0.1 liters. Choice B (10 ml) is incorrect as it also represents the conversion of 0.01 liters. Choice D (1000 ml) is incorrect as it represents the conversion of 1 liter, not 0.1 liter.

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: C

Rationale: To convert 0.16 into a fraction, you write it as 16\100, which simplifies to 4\25. This fraction is in its simplest form and accurately represents the original decimal value without further reduction. Choice A (16\1000) is incorrect because the fraction is not simplified, and Choice D (4\50) is incorrect as it simplifies to 2\25, not representing the original decimal value. Therefore, Choice C is the correct answer.

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.