ans is given but please explain how step by step.

Khan Incorporated has an investment project with the following parameters. . It is expected to generate a payment of $550 every six months in perpetuity. The first cash inflow is six months from now. The cost of capital is 7% per six months (effective). The project requires an initial investment of $8,000 now. What is the net present value of this project? Answer: $142.86