John decided to leave his job and open a bookshop in the city center. He was working as an engineer before and getting an annual salary of $35000. For the bookshop he paid $20000 for his worker, $15000 for rent, $10000 for utilities. He used his savings that was equivalent to $60000 at an interest rate of 7%. He bought all the books that he planned to sell by his savings. If he opens his bookshop in mall rather than city center his profit was predicted to be $25000. At the end of the first year his revenue from sales was identical to $210000. For John a) Calculate the implicit costs. b) Calculate the explicit costs. c) Calculate the total cost. d) Calculate his profit/loss. e) Should he continue to the business or go back to his job?