Markowis Corporation sells three different models of mosquito "zapper." Model A12 sells for $50 and has variable costs of $40. Model B22 sells for $100 and has variable costs of $70. Model C124 sells for $400 and has variable costs of $300. The sales mix of the three models is: A12, 60%; B22, 15%; and C124, 25%. What is the weighted-average unit contribution margin?