Answer:
Total interest = $3.41
Step-by-step explanation:
Since she can pay $72 each month we can divide the payments on monthly basis till all the money is paid.
The annual interest rate is 24.7%, so the monthly rate will be 24.7 ÷ 12= 2.058%
For the first month
With payment of $72 the remaining amount will be 189.56 - 72 = $117.56
Interest paid will be 0.02058 * 117.56 = $2.42
Total amount owed now will be 117.56 + 2.42 = $119.98
For the second month another payment of $72 is made
The remaining will be 119.98 - 72 = $47.98
Interest charged will be 0.02058 * 47.98 = $0.99
The amount owed will be 47.98 + 0.99 = $48.97
In the third month she will pay the remaining $47.98 which is within her monthly limit
Total interest paid = Sum of Amount paid each month - Initial amount spent
Total interest = {(72 * 2) +48.97} - 189.56 = $3.41
