One of your customers is delinquent on his accounts payable balance. Youve mutually agreed to a repayment schedule of $500 per month. You will charge 1.8 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? PLEASE answer in EXCEL FORMULA!!!!!!!!!!!!!!!!!!!!

monthly payment $500, Rate per month 1.80%, Current Balance $18,000, months until paid off = ?

PLEASE answer in EXCEL FORMULA!!!!!!!!!!!!!!!!!!!!