HELP Sam and Carlos are buying a total of 30 music downloads . The premium downloads cost $ 2.00 and the basicdownloads cost $1.50 . They end up spending a total of $47.00 . Write a system of equations to determine how many basic downloads and premium downloads they purchased.

Me find the missing dimension of a triangle height: 7 in., area: 21^2

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

In a singing competition, there are 150 participants. at the end of each round, 40% of the participants are eliminated. how many participants are left after n rounds?