11. Arwen sells previously enjoyed rare CDs for $5.00 each and rare LP vinyl records for $7.00 each. She sold a total of 1200 CDs and records in a particular month, with total sales of $6, 760. a. Defining an appropriate variable, write an equation that will determine the number of rare CDs sold that month. [2 marks] b. How many of each type were sold that month (i.e. the number of CDs and the number of LPs)? [2 marks] c. What was the total revenue received for sales of just CDs that month? [1 mark]