21. Calculating Number of Periods [LO3] One of your customers is delinquent on his accounts payable balance. You've mutually agreed to a repayment schedule of $450 per month. You will charge 1.3 percent per month interest on the overdue bal- ance. If the current balance is $18,000, how long will it take for the account to be paid off? 22. Calculating EAR ILO41 Friendly's Quick Loans, Inc. offers you "three for four