Consider $30-$year, $$250,000$ variable$-$rate mortgage $($ARM$)$ offers a first$-$year teaser rate of $2\mathrm{.}5\%.$ For the first $12$ months. After the first $12$ months, the rate is adjusted based on the actual interest rate in the market.$($a$)$ What is the monthly payment during the first $12$ months?$($b$)$ What is the monthly payment The $3$ years