Answer:
The "total loan cost" formula is what you'll need (and it is attached).
Interest =1.25 / 1,200 = 0.0010416667
and "n" is number of months (6 years = 72 months)
Total Loan Cost = (r*p*n) / 1 -((1 + r)^-n)
Total Loan Cost = (0.0010416667 * 12,000 * 72) / 1 -((1.0010416667)^-72)
Total Loan Cost = 900 / 1 -0.9277797019
Total Loan Cost = 900 / 0.0722202981
Total Loan Cost = 12,461.87
Explanation: