Harper just drank a cup of coffee to help her stay awake. The coffee had 140 milligrams of caffeine in it. If her body processes 5% of the caffeine every hour, how much will be left in 8 hours?
5% of 140 is 7, and if its 5% every hour then you take away 7 for every hour, if there are 8 hours then its 7*8=56. You then subtract that number from 140 which is equal to 84
