You are asked to determine the optimal economic life of the following project. It has an engineering or physical life of 4 years. The cost of capital is 8% and all cash flows except the initial cost are end of year cash flows.

Year Net operating cash flow                      Net terminal cash flow

0 (50,000)

1 20,000                                                      35,000

2 15,000    25,000

3 10,000                                                      15,000

4 5,000                                                          5,000