Which of the following is the correct way to write two grains in the apothecary system?

• A. 2 g
• B. 2 gr
• C. 2 oz
• D. 2 mg

Answer: (B)

Verified step by step guidance

1. Understand that the apothecary system is an old system of measurement used primarily in pharmacy, where 'gr' stands for grains.
2. Recognize that the symbol for grains in the apothecary system is 'gr', not 'g' which stands for grams in the metric system.
3. Note that 'oz' stands for ounces, which is a different unit of mass, and 'mg' stands for milligrams, a metric unit.
4. Therefore, to write two grains correctly in the apothecary system, you use the number followed by 'gr', like this: \$2\ gr$.
5. Confirm that the correct notation for two grains is \$2\ gr$, distinguishing it clearly from metric units and other apothecary units.