15. Three business graduates are considering opening a FBO. This is an alternative for other jobs they could pay them up to $60,000 each. They are planning to lease a fully equipped FBO for $80,000. The operating costs include; insurance, $10,000; materials and supplies, $.40 per unit. They can charge an average price of $10 for the services. a. Calculate total annual accounting costs. b. Calculate total annual economic costs.