Use the information provided below to answer the following questions:

Sales ($50 per unit)

$10,000

Cost of goods sold (all variable costs)

6,000

Fixed costs

2,800

a.How many units would the company need to sell to earn $4,000 in operating income?

b.How many units would the company need to sell to earn $4,000 in net income if the tax rate is 20%?

c.By how much would operating income change from part (b) with a 10% increase in units sold?