Here’s the table:
I think the payment period is a month, but I don’t understand why it’s 100.
The image is taken from this Excel exercise: http://web.utk.edu/~dhouston/excel/exer3.pdf
It is the 100th month of the mortgage term.
PMT() function in Excel I generated this amortization schedule with the variables in your question:
For some reason rather than showing the whole amortization table they chose to let you calculate for any given month what the split between principal and interest would be.
Edit: Added the formula text in the next cell over on the top portion to show interest percentage used and
PMT() function format.