ABC Audio sells headphones and would like to earn an after-tax profit of $400 every week. Each set of headphones incurs variable cost of $5 and sells for $10. Rent and other fixed costs are $200 per...

ABC Audio sells headphones and would like to earn an after-tax profit of $400 every week. Each set of headphones incurs variable cost of $5 and sells for $10. Rent and other fixed costs are $200 per week; the income tax rate is 20%. How many headphones must ABC sell per week to meet its profit goal?