The concentration (in milligrams) of a drug in a patient’s bloodstream decays at a…
MATHEMATICS · Single correct · AP · Calculus AB · Differential Equations · Differential Equations
Problem
The concentration C (in milligrams) of a drug in a patient’s bloodstream decays at a rate proportional to its concentration. Immediately after dosing, C(0)=120. After 2 hours, the concentration is 70 mg. The patient may safely take the next dose when the concentration first falls below 25 mg. Which of the following is closest to the earliest permissible time after the initial dose?
(a) 3.9 h
(b) 9.3 h
(c) 5.8 h
(d) 7.5 h