Answer:
[tex] PMT= 1957.850[/tex]
Explanation:
For this case the total payment is $320000, and she pays $40000 so the remain amount to pay would be:
$320000-40000=$ 280000
For this case we assume that the annual interest rate is APR=5.7% =0.057 on fraction.
The total number of years are 20. For this case n represent the number of payments per year and since we have monthly payments then n =12.
In order to find the PMT we can use the following formula:
[tex] PMT= \frac{P(\frac{APR}{n})}{[1-(1+\frac{APR}{n})^{-nt}]}[/tex]
On the last expression the APR needs to be on fraction and P represent the principal amount, for this case P = $280000. So if we replace we got:
[tex] PMT= \frac{280000(\frac{0.057}{12})}{[1-(1+\frac{0.057}{12})^{-12*20}]}[/tex]
[tex] PMT= 1957.850[/tex]
And we can verify this using the following excel function: "=PMT(0.057/12,12*20,-280000)"