How do I solve 9.6 a-b?

9.6 Consider the following uneven cash flow stream: Year Cash Flow 0 $ 0 1 250 2 400 500 4 600 5 600 a. What is the present (Year 0) value if the opportunity cost (discount) rate is 10 percent? b. Add an outflow (or cost) of $1,000 at Year 0. What is the present value (or net present value) of the stream