18. Calculate the net present value (NPV) for the following 20-year projects. Comment on the acceptability of each. Assume that the firm has an opportunity cost of 14 percent.

a. Initial cash outlay is $15,000; cash inflows are $13,000 per year.

b. Initial cash outlay is $32,000; cash inflows are $4,000 per year.

c. Initial cash outlay is $50,000; cash inflows are $8,500 per year.