ANSWER PROBLEM $3$ ONLY

Problem$3-$ Consider Problem $1.$ For payments $1-11$ we pay the regular payment computed in Problem$1.$ At time k$=12($payment #$12)$ we send additional G$=15,000$ towards the principal. After that we keep paying the regular payment computed in Problem$1.$ Questions $-($i$)$ at what time the loan will be paid off, $($ii$)$ compute the final payment, $($iii$)$ compute the total interest paid on this mortgage under the new payment, $($iv$)$ show the first two lines, lines $11,12,13,$ and the last two lines of the amortization table, $($v$)$ compute WAL and K$05$

Problem$1-$ We borrow a mortgage $$350,000$ at $8\mathrm{.}5\%$ for $30$ years. Questions $-($i$)$ compute regular monthly payment, $($ii$)$ compute the final payment, $($iii$)$ compute the total interest paid on this mortgage, $($iv$)$ show the first two and the last two lines of the amortization table, $($v$)$ compute WAL and KProblem$2-$ Consider Problem $1.$ Assume that each month we pay addition $$20($payment M $=$ regular payment $+20).$ Questions $-($i$)$ at what time the loan will be paid off, $($ii$)$ compute the final payment, $($iii$)$ compute the total interest paid on this mortgage under the new payment, $($iv$)$ show the first two and the last two lines of the amortization table, $($v$)$ compute WAL and K$05$

answer problem $3$ only