4. Lily purchases $15,000 worth car and establishes the 20-year loan with yearly payment at the end of year. Each of the first ten payments equals 200% of the amount of interest due. For the rest of ten payments, the level payment $X is applied. The lender charges interest at an annual effective interest rate of 8%. (a) [3 points] Calculate the outstanding balance at the end of year 10 immediately after the 10th payments is repaid. (b) [3 points) Calculate the level payment $X applied for the last ten payments. (c) [4 points) Calculate the principal repaid on the 14th payment