Aroller coaster at a theme park takes fans on an exciting ride. in the first 20 seconds, it carries its passengers up a 30-meter hill, plunges them down 30 meters, and takes them back up a 15-meter rise. how much higher or lower from the start of the ride are they after these 20 seconds?

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