EXERCISE $3\mathrm{.}4$

Mr$.$ Kenneth borrowed $10,000$ dollars at the beginning of last month. The monthly rate is $1\%,$ and is charged at end of each month. Mr$.$ Kenneth wishes to pay off his debt by paying $$400$ dollars each month, starting beginning of this month. How long will it take in order to pay off the entire debt? $($Refer to Figure $3\mathrm{.}3\mathrm{.}8$ for timing of payments.$)$

Using the PMT and GOAL SEEK functions on excel