Rosanne takes 190 milligrams of an antibiotic. Every hour, her body breaks down 50% of the drug. How

Rosanne takes 190 milligrams of an antibiotic. Every hour, her body breaks down 50% of the drug. How much will be left after 5 hours

Let the antibiotic amount be A(h) where h is the amount of hours after ingestion. We have:
A(h) = 190 * (1 - 0.5)^h
A(h) = 190 * (0.5)^h

The problem asks for A(5):
A(5) = 190 * (0.5)^5
A(5) = 190 * 0.03125
A(5) = 5.9375 milligrams