Answer: Since Frank made his most recent EMI payment today, Frank needs 76,136.52 in order to pay off his mortgage today.
We follow these steps to arrive at the answer:
We first calculate the EMI on loan taken out:
The EMI is nothing but P (constant amount paid or received periodically) in the Present Value of an Annuity formula. The formula is
![\mathbf{PV_{Annuity} = EMI* \left[ \frac{1 - (1+r)^{-n}}{r} \right]}](https://tex.z-dn.net/?f=%5Cmathbf%7BPV_%7BAnnuity%7D%20%3D%20EMI%2A%20%5Cleft%5B%20%5Cfrac%7B1%20-%20%281%2Br%29%5E%7B-n%7D%7D%7Br%7D%20%5Cright%5D%7D)
Substituting the values from the question we get,
150000 = EMI* \left[ \frac{1 - (1+\frac{0.05}{12})^{-(25*12)}}{\frac{0.05}{12}} \right]
Solving we get,
![150000 = EMI* \left[\171.06\right]](https://tex.z-dn.net/?f=150000%20%3D%20EMI%2A%20%5Cleft%5B%5C171.06%5Cright%5D)


We then construct the Amortization table attached below. At the end of 16 years or 192 periods (
), we can see that the principal outstanding is $76,136.52.