solve the cost of capital, and the economic profit

Harvey quit his job at State University where he earned $45,000 a year. He figures his entrepreneurial talent or foregone entrepreneurial income to be $5,000 a year. To start the business, he cashed in $100,000 in bonds that earned 10 percent interest annually to buy a software cpany, Extreme Gaming. In the first year, the firm sold 11,000 units of software at $75 for each unit. Of the $75 per unit. $55 goes for the costs of production, packaging, marketing, employee wages and benefits, and rent on a building