10. Jina is buying a car for $30,000 using a 60-month car loan with an interest rate of 9% compounded monthly and level (end-of-month) payments. The amount of each payment is $P. In reality, for the first two years, Jina makes the required payment (that is, $P). Beginning with the first payment in the third year, Jina begins paying twice the required payment (that is, $2P). Jina will completely pay off her loan by making a smaller final payment. (a) Find the value of P. (b) Determine the total number of payments that Jina will make.