Please help me! :( I don't understand

How to solve it and what thw answer is

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

An empty bucket is placed under a faucet dripping at a constant rate of 4 milliliters per minute. with the given information, which of these statements is a reasonable conclusion? a there will be 24 milliliters of water in the bucket after 16 hour. b there will be 60 milliliters of water in the bucket after 14 hour. c there will be 160 milliliters of water in the bucket after 20 minutes. d there will be 100 milliliters of water in the bucket after 40 minutes.