Business Math
posted by Liz .
Joyce took out a loan for $21,900 at 12 percent on March 18, 2000, which will be due on January 9, 2001. using ordinary interest, Joyce will pay back on January 9 a total amount of:
Answer: $24,068.10
Ordinary interest is 360
March 18 = 77 days
January 9  9 days
Interest = (P) Principal x (I) Rate x (T)Time
T = Exact number of days/360
Please show step by step. Thank you!

okay, I figure how to solve my problem.
Principal: $21,900
Interest Rate: 12%
Date borrowed: March 18 = 77 days
Date repaid: January 9 = 9 days
365  77 = 288 + 9 = 297 days
Interest = Prinicpal x Rate x Time
I = $21,900 x .12 x 297/360
I = $2,168.10
Maturity Value = Principal + Interest
MV = $21,900 + $2,168.10
MV = $24,068.10