Problem
John borrowed $20,000 to purchase a new car at an interest rate of i(12) = 6% amortized over 5 years, paid monthly. Unfortunately, after making 20 payments on time, John fell ill and was forced to miss 5 consecutive payments. The bank agreed to allow him to restart making payments, but they would not agree to extend the original amortization period (thus the loan must be fully paid under the new terms on the same date it would have been under the original terms). What was his original monthly payment, and what will it be under the new terms?