A physician ordered phenobarbital ½ gr. How many 15 mg tablets should the patient receive?

1
2
3
4

1

Rationale: By cross-multiplying and dividing as follows, 1 gr -------- 60 mg = ¼ gr ------- X mg. We find that X = 15 mg. Then, 15 mg -------- 1 tab = 15 mg -------- X tab. Therefore X = 1 tablet.