Carol Miller went to Europe and forgot to pay her $600 mortgage payment on her New Hampshire ski house. For her 53 days overdue on her payment, the bank charged her a penalty of $25. What was the rate of interest charged by the bank? (Use 360 days a year. Do not round your intermediate calculations. Round your answer to the nearest hundredth percent.)

1 answer

600*(r/360)*53 = 25
r = 15/53 = 0.2830 = 28.30%