18. You are considering buying a car worth $30,000. The dealer, who is anxious to sell the car, offers you an attractive financing package. You have to make a down-payment of $3,500, and pay the rest over 5 years with annual payments. The dealer will charge you interest at a constant annual interest rate of 2%, which may be different from the market interest rate. (a) What is the annual payment to the dealer? (b) The dealer offers you a second option: you pay cash, but get a $2,500 rebate. Should you go for the loan or should you pay cash? Assume that the market annual interest rate is constant at 5%. Note: the tradeoff between the two options is that in the first case, you can finance your purchase at a relatively low rate of interest. In the second case, you receive a lump-sum cash rebate