2. The operating cash flow for the acquisition and maintenance of a clamshell for excavation is given by At in the following table (no salvage value). Three financing plans, each charging a borrowing rate of 6 percent but having a different method of repayment, are represented by three different cash flows of At. Find the net present value before tax for each of the three combined cash flows AAt for operating and financing if the beforetax MARR is specified to be 6 percent. Note: Read Art 6.11 for Combined Cash Flow (Reference - Chapter 6)