Plz help me

This question awards 100 ! i really don’t want to fail i will also mark you !

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

Iknow its nothing to do with education, but what type of thing should i wrote here? ? : ) its for mcdonald's btw.