Answer: 67.7%
Step-by-step explanation:
Contribution Margin ratio = (Sales per units - Variable cost per unit) / Sales per unit
Variable cost per unit = (Manufacturing + Marketing + Administrative)/ Units sold
= (115,000 + 22,000 + 42,000) / 30,000
= $5.97
Contribution Margin ratio = ( 18.50 - 5.97)/ 18.50
= 67.7%