Answer:
Contribution Margin 13.6
Contribution Margin Ratio 0.68
Variable Cost ratio 0.32
Step-by-step explanation:
Sales Price 20
Direct materials 2.10
Direct labor 1.25
Variable factory overhead 2.00
Variable selling and administrative expense 1.05
Total Variable cost 6.4

20 - 6.4 = 13.6 Contribution Margin

13.6/20 = 0.68

6.4/20 = 0.32