Correct Answer: B

Rationale: The calculation of 0.4 divided by 40 results in 0.01, which can be expressed as 1/100. This fraction is the correct representation of the division of 0.4 by 40. Choice A, 1/100, is the correct answer as it accurately reflects the division. Choices C and D, 1/400 and 1/40000 respectively, do not correctly represent the division operation performed on 0.4 and 40, leading to incorrect results and are therefore not the correct answers.

Correct Answer: A

Rationale: To convert 0.07 to a fraction, we note that 0.07 is equivalent to 7/100. This is because 0.07 can be read as 7 hundredths. Thus, the correct fraction form is 7/100. Choices B, C, and D are incorrect. Choice B, 1/10, is the fraction equivalent to 0.1, not 0.07. Choice C, 1/20, and Choice D, 1/50, are also incorrect as they do not represent the value of 0.07 when converted to a fraction.

Correct Answer: B

Rationale: The prefix 'milli' means one-thousandth, which is equivalent to 0.001 of the base unit. For instance, 1 millimeter is equal to 0.001 meters. Choice A (0.01) is incorrect as it represents one-hundredth, not one-thousandth. Choice C (0.0001) is incorrect as it signifies ten-thousandth, not one-thousandth. Choice D (0.00001) is incorrect as it stands for one-hundred-thousandth, not one-thousandth.

Correct Answer: A

Rationale: To convert milliliters to liters, you need to divide by 1000 since there are 1000 milliliters in a liter. Therefore, the correct conversion factor is 0.001 liters (1 liter = 1000 milliliters). Choice B (0.01 liters) is incorrect as it suggests dividing by 100, which is not the correct conversion. Choice C (1 liter) is incorrect because it is the equivalent value in liters, not the conversion factor. Choice D (10 liters) is incorrect as it is not the correct conversion of milliliters to liters.

Correct Answer: A

Rationale: The decimal 0.004 can be represented as a ratio of 4/1000, which simplifies to 1/250, making the ratio 1:250. The correct answer is A. Choices B, C, and D are incorrect because they do not reflect the correct conversion of 0.004 into a simplified ratio. Choice B simplifies to 1:5, Choice C simplifies to 1:20, and Choice D simplifies to 9:20, none of which accurately represent the ratio of 0.004.