The table below shows the number of marbles of different colors in a bag: Color of Marbles Number of Marbles
Pink 4
Blue 8
Green 1
Bryan draws a marble from the bag randomly without looking. He then draws another marble from the bag without replacing the first one. Which expression shows the probability of drawing blue marbles in both the trials?
A. 8 / 13* 7 / 13
B. 8 / 13 + 7 / 12
C. 8 / 13 * 7 / 12
D. 8 / 13 + 7 / 13

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