Luke's Diner sells three different kinds of coffee in 5 lb bags.

• The light roast sells for $30 and has variable costs of $18
• The medium roast sells for $50 and has variable costs of $30
• The dark roast sells for $65 and has variable costs of $30

The sales mix of the three sets is: Light, 50%; Medium, 30%; and Dark, 20%.

What is the weighted-average unit contribution margin?