With a few discreet questions, you find out that he drank 8 shots of tequila at 10pm and drove your car home at 3am the next day. each shot is approximately 40 ml and the tequila was 80 proof (40% ethanol by volume). if you assume that the shots were drunk very quickly and rapidly absorbed, you may assume that your classmate began with 7 shots worth of alcohol in his central compartment at 10pm. if only you knew his clearance rate, you'd be able to calculate his blood alcohol level at 3am!