One of your customers is delinquent on his accounts payable balance. You've mutually agreed to a repayment schedule of $750 per month. You will charge 1 . 90 percent per month interest on the overdue balance. If the current balance is $18, 000, how long will it take for the account to be paid off? (Do not round intermediate calculations and round your final answer to 2 decimal places. (e. g. , 32. 16))