$(1)$ Determine the Pauback Peried.

$\backslash$table$[[$YR CASH ROW,,$],[0,-100,],[1,25,],[2,25,],[3,25,],[4,25,],[vdots,$vdots,$]]$

$(2)$ Determive Break$-$Even Ammual Revenue. $($Always draw CFD$)$

First cost: $$3$