need help solving for a, b, and c.

Average rate of return, cash payback period, net present value method for a service company The St. Louls to Seattle Railroad is considering acquiring equipment at a cost of $140,000. The equipment has an estimated life of 10 years and no residual value. It is expected to provide yearly net cash flows of $70,000. The company's minimum desired rate of return for net present value analysis is 15%. Compute the following: a. The average rate of return, giving effect to straight-line depreciation on the investment. If required, round your answer to one decimal place. Compute the following: a. The average rate of return, giving effect to straight-line depreciation on the investment. If required, round your answer to one decimal place. W b. The cash payback period. c. The net present value. Use the above table of the present value of an annuity of \$1. Round to the nearest dollar. If required, use a minus sign to indicate negative net present value for current grading purpose