How to solve without excel

Alan smith wats to buy a used Porsche at a price of $40,000. A. The dealer told him that all he has to pay is only $8,000. The dealer will provide him a car loan at 12% annual rate over next 4 years. How much does Alan has to pay each month for this car loan? B. Suppose the dealer clain that "I am going to offer Alan a 0% rate" package down payment of $40,000 right now and $1,000 for each of the next 36 months. A rate of 0%. If alan believes that the average rate of car loans should be 12%, what is the maximum discount alan can get if he is able to pay cash right now