the amount of a 10 mg dose of a certain antibiotic decreases in your bloodstream at the rate of 16% per hour. write an exponential decay function to model this situation. then find the amount the antibiotic will decrease in 4 hours

Mallory has been offers two different jobs. she can baby sit for 6 hours a week and get $8.50 an hour. or she can work at the library for 14 hours a week and make $5.50 an hour. which job will allow her to save the most money after 6weeks?