John is working part-time in an office. he works 30 hours per week and earns $600 each week. he currently has $2,700 in a savings account. john needs to spend $3,780 on car repairs. he sets aside $492 a week for his usual expenses. john’s savings account pays 4% simple interest. if the principal is
$2,700, what will the balance be after interest is added?

Suppose that 3% of all athletes are using the endurance-enhancing hormone epo (you should be able to simply compute the percentage of all athletes that are not using epo). for our purposes, a “positive” test result is one that indicates presence of epo in an athlete’s bloodstream. the probability of a positive result, given the presence of epo is .99. the probability of a negative result, when epo is not present, is .90. what is the probability that a randomly selected athlete tests positive for epo? 0.0297