Contemporary Mathematics for Business & Consumers 8th Edition by Robert Brechner,Geroge Bergeman

Exercise 87

Richie Powers is the owner of American Eagle Boats, a manufacturer of custom pleasure boats. Because of the economic recession and slow boat sales recently, American Eagle has begun accepting promissory notes from its dealers to help finance large orders. This morning American Eagle accepted a 90-day, 9.5% promissory note for $600,000 from Champion Marine, one of its sales dealers.
You are a manager for Atlantic Bank, and Richine is one of your clients. Atlantic's discount rate is currently 16%. Richie's goal is to discount the note as soon as possible, but not until the proceeds are atleast equal to the face value of the note, $600,000.
a. As his banker, Richie has asked you to "run the numbers" at ten-day intervals starting with day 20 and advise him as to when he can discount the note and still receive his $600,000.
b. (Challenge) Calculate the exact day the note should be discounted to meet Richie's goal.