Enola, Inc., manufactures a product that sells for $400. The variable costs per unit are as follows: Direct materials $100 Direct labor 80 Variable manufacturing overhead 50 During the year, the budgeted fixed manufacturing overhead is estimated to be $500,000, and budgeted fixed selling and administrative costs are expected to be $250,000. Variable selling costs are $20 per unit. 

Required: 

a. Determine the break-even point in units. 

b. Determine the number of units that must be sold to earn $300,000 in profit before taxes. 

c. Determine the number of units that must be sold to generate an after-tax profit of $90,000 if there is a 40 percent tax rate.