Convert 3,450 grams to milligrams (mg).

Correct Answer: B

Rationale: To convert grams to milligrams, you need to multiply by 1,000 since there are 1,000 milligrams in a gram. Therefore, 3,450 grams 1,000 = 3,450,000 milligrams. Choice A (34,500 mg) is incorrect because it represents the result for converting grams to milligrams by a factor of 10 (not 1,000). Choice C (3,450 mg) is incorrect as it represents the original amount in grams, not the converted amount to milligrams. Choice D (3,450,000 mg) is incorrect as it is the same as the correct answer but with the comma in the wrong place, which would imply converting kilograms to milligrams rather than grams to milligrams.

Correct Answer: B

Rationale: To convert centimeters to kilometers, you need to divide by 100,000 since there are 100,000 centimeters in a kilometer. Therefore, 35.4 cm · 100,000 = 0.000354 km. Choice A (0.00354 km) is incorrect as it represents dividing by 10,000, not 100,000. Choice C (0.00345 km) is incorrect as the last digit is different from the correct answer. Choice D (0.0345 km) is incorrect as it represents dividing by 1,000, not by 100,000.

Correct Answer: B

Rationale: The base unit for mass in the metric system is grams. Grams are the fundamental unit of mass in the metric system, representing smaller quantities than kilograms and tons. Milligrams are a smaller unit of mass, kilograms are a larger unit, and tons are even larger units. Therefore, the correct choice is grams.

Correct Answer: B

Rationale: The correct answer is B: derived units. When base units (such as grams or milliliters) are combined, as seen in g/mL (grams per milliliter) for density, they form derived units. Derived units measure complex quantities that are derived from combinations of base units. Choice A, 'combined units,' is incorrect as it does not specifically refer to the formation of new units from base units. Choice C, 'base units,' is incorrect because base units are the fundamental units from which all other units are derived, not the combinations of units. Choice D, 'calculated units,' is incorrect as it does not accurately describe the concept of combining base units to form a new unit like g/mL for density.

Correct Answer: B

Rationale: The correct formula for calculating the volume of a solid object is V = L x W x H, where L represents the length, W represents the width, and H represents the height. Choice A (V = W/L) is incorrect as it represents a division operation, not multiplication. Choice C (V = W/H) is incorrect as it does not account for the width and height. Choice D (V = L/W) is incorrect as it represents the inverse operation of what is needed to calculate volume.