Answer:
The answer is C
Step-by-step explanation:
The after-tax amount Charles from saling his 2004 Neon is : 6,591 x 80% x ( 1 - 6.88%) = $4,910
The total amount Charles has to pay for the new car : $ 21,450 + 1,089 + $124 = $22,663
The total amount Charles has to get from finance plan : $ 22,663 - 4,910 = $17,753
For the finance plan, we have: Monthly IR = 12.28% /12 = 1.023%; Number of payment(N) = 12 x 3 = 36; Present value (PV) = Financing amount = $17,753
We apply the present value formular for annuity to find the equal payment Charles needs to pay monthly : C = (PV x Monthly IR) : ( 1 - (1+i)^(-n) ) = $592
So the total repayment needs to be make in Charles' finance plan = $592 x 36 = $21,312
The total interest expenses is: Total repayment - Financing Amount = $21,312 - $17,753 = $3,559 => percentage of total interest expenses in the amount paid = 3,559/21,312 = 16.70%