In a bag of blue and yellow marbles, the ratio of blue marbles to yellow marbles is 3: 5. if the bag contains 60 yellow marbles, how many blue marbles are there?

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

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

The letters g e o r g i a are placed in a bag . if you picked a card and knew it was a vowel , what is the probability that it is an a ?