Marcie bought a total of 20 used books and cds during a yard sale for a total of 54.50$. of books cost 1.50$ each and cds 5$ each, how many of each did she buy? 1 define your variables ,- what are you solving for 2 set up equations - using the information given 3 solve the system using your method of choice

Four airplanes carrying a total of 400 passengersarrive at the detroit airport. the airplanes carry, respectively,50, 80, 110, and 160 passengers. a) one of the 400 passengers is selected uniformly at random. let x denote the number of passengers that were on theairplane carrying the randomly selected passenger. find var(x)for x as given in the problemb) one of the 4 airplane drivers is also selected uniformly atrandom. let y denote the number of passengers on the chosen driver’s airplane. find var(y) for y as given in the problem

Mr. roseanne will buy 12 1/2 pounds beef for for a cookout. the price for the first 3 pounds of beef is $4.99 per pound. after that, the price is $4.49 per pound. how much will mr. roshan pay for the beef

The hockey team has been great! in 2008 they won 20% more games than in 2007. in 2009 they won 50% more games than in 2008. what was their overall percentage increase from 2007 through 2009?