How many milligrams are in 1 grain?

• A. 50 mg
• B. 60 mg
• C. 30 mg
• D. 100 mg

Answer: (B)

Converting grains to milligrams is about translating a traditional apothecary unit into a modern metric unit. One grain is exactly about 0.0648 grams, which is 64.8 milligrams.

From the given choices, 60 mg is the closest to the actual 64.8 mg, making it the best approximation among the options. The other values are farther away: 50 mg is about 14.8 mg off, 30 mg is about 34.8 mg off, and 100 mg is about 35.2 mg off.