Answer:
a. 37.5% = ($80 – $50) ÷ $80, or ($480,000 – $300,000) ÷ $480,000
b. $30 per unit = $80 – $50
c. Sales………………………………… $480,000 (6,000 units × $80 per unit)
Variable costs……………………… 300,000 (6,000 units × $50 per unit)
Contribution margin……………… $180,000 (6,000 units × $30 per unit)
Fixed costs………………………… 50,000
Income from operations………… $130,000