$3-$ A proposed wind farm installation is based on the use of thirty $2MW$ wind turbines. The installed

capital cost is estimated at $$\frac{1000}{k}W$ and the annual operation and maintenance costs are estimated

to be $3\%$ of the original capital cost. Financing for the project is to come from two sources: $1)$ A $20-$

year loan at $7\%(75\%),$ and $2$