Help please I don’t understand this problem

Acredit card advertises an annual interest rate of 23%. what is the equivalent monthly interest rate?

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

Nine people are going to share a 128-ounces bottle of soda. how many ounces will each person get drink? choose the correct equation and answer for this situation