posted by liz .
After several drinks, a person has a blood alcohol level of 200 mg/dL (milligrams per deciliter). If the amount of alcohol in the blood decays exponentially, with one fourth being removed every hour, find the person's blood alcohol level after 2 hours.
after 1st hr: 200 - 200/4 = 200 - 50 = 150 mg/dL remaining,
after 2nd hr: 150 - 150/4 = 150 - 37.5 = 112.5 mg/dL remaining.