Emily decides to start her own software company. She can earn $150,000 in revenue from this company for three years. Here explicit cost for equipment and labor are $60,000 per year. Her implicit cost is the foregone opportunity of working as a high school math teacher at a salary of $70,000 per year. All revenues are received, and costs borne, at the end of each year. If the interest rate is 5 percent, determine the present value of the stream of:
a) Accounting profits
b) Economic profits