answer; /// i believe the correct answer is (all of the above);
The interest expenses Raul saves by making the partial repayment on the 90th day of the note is: $360.5.
Assume the interest calculation is based on a 360-day-per-year basis.
By making partially repayment of $5,000 at the 90th day of the note, Raul has saved the interest expenses incurred for the $5,000 principal for the remaining 180 days of the note ( calculated as 270 days - 90 days).
So, the interest expenses saving is calculated as:
5,000 x 14.42% * 180/360 = $360.5.
So, the answer is $360.5.