The 50 pack is a better deal.
Work Step by Step
By dividing the number of cds by cost, you can how many cds you are getting per dollar, and which ever has more cds per dollar is the better deal. $30\div9.50=3.16$ In the 30 pack, you are getting 3.16 cds per dollar. or $50\div13=3.85$ In the 50 pack, you are getting 3.85 cds per dollar. Therefore, the 50 pack is a better deal because you are getting .69 more cds per dollar.