Jiahao G. answered 03/07/21
Best Trainer for Finance Exams (CFA, CFP)
Step 1. Calculate the present value of your future payments in the next month (using the financial calculator):
N = 35, I/Y = 6.7% / 12 = 0.558%, PMT = 606, FV = 0, CPT PV = 19,218.831380
Step 2. Since you pay 1,400 more next month, the present value calculated in Step 1 will be reduced by 1,400 to 17,818.831380. Using the new present value, you can get the number of months of your future payments.
PV = -17,818.831380, PMT = 606, I/Y = 0.558%, FV = 0, CPT N ≅ 32
So the new time left to pay off your loan will be 32 months? Thus, you reduce the amount of time remaining on the loan by approximately 3 (=35 - 32) months.