It takes Bethany 9 hours to proof a chapter of Hawkes Learning Systems' College Algebra book and it takes Nina 5 hours. How long would it take them working together

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

Which spreadsheet would be used to compute the first nine terms of the geometric sequence a^n=32•(1/2)n-1

Astocks price gained 3% in april and 5% in may and then lost 4% in june and 1% in july during which month did the stocks price change the most