Question: The rate at which a drug leaves the bloodstream and passes into the urine is proportional to the quantity of the drug in the blood at that time. If an initial dose of Q0 is injected directly into the blood, 20% is left in the blood after 3 hours.
(a) Write and solve a differential equation for the quantity, Q, of the drug in the blood after t hours.
(b) How much of this drug is in a patient's body after 6 hours if the patient is given 100 mg initially?