I'll get you started, and you can finish.
At the end of the first year, Korey can expect to make 12000*(1.06).
At the end of year 2, that rises to 12000*(1.06)*(1.06) = 12000(*(1.06)^2
So, at the end of N years, Korey can expect profits of 12000*(1.06)^N