Karas company sells two kinds of calculators: regular and graphing. Graphing calculators are sold for $250 and make up 40% of the sales mix. Regular calculators sell for $50 and make up 60% of the sales mix. The variable costs for the regular calculators total $30, and the variable cost for the graphing calculators total $100. What is the weighted-average unit contribution margin for these products?

• A :

  $72
• B :

  $84
• C :

  $118
• D :

  $130