Use a 360-day year to compute interest

Since this is homework... what did you get for an answer and how did you go about it.

there is a disconnect here, that is basic mathematics; let me see, 9%; that's 0.09 or 9/100, and then 90 days; that's 0.25 of a year or if you want to be more precise 90/365, so you string it all together and throw in 36000, and if you don't get it at this point don't study accounting because it only gets harder from here