MATH RADICALS

Hi, We are grade nine students here at St.Paul's school. Our names are Dee and Jennifer. Like most people our age we enjoy listening to music, watching television ( Friends, ER, Party of Five and The Simpsons.) and playing sports. Some of our favorite sports are soccer and skating. Lots of times during the winter we go skating on the lake behind Dee's house. ( sometimes we end up swimming *laugh*)
Problem: Dee and Jennifer go to the mall. Dee has $51.44 and Jennifer has $32.56, for a total of $84.00. They can purchase 3 cassettes for the price of 2 cd's. If they buy 3 cd's and 6 casstte's for $84.00 then the price of a single cd is how much?