Based on Exhibit $7-7,$ what would be the monthly mortgage payments for each of the following situations? $($Round your answers to $2$ decimal places.$)$

$\backslash$table$[[$a$.A$$$162,500,15-$year loan at $7\mathrm{.}5$ percent.$],[$b$.A217,500,30-$year loan at $7\mathrm{.}5$ percent.$],[$c$.A$$$195,000,20-$year loan at $7\mathrm{.}5$ percent.$]]$