Finding IRR and incremental IRR without using Excel or trial and error method.

And may you help me on Question 2 part C ( probability index )

1)** [6-20] Consider the following cash flows on two mutually exclusive projects for Tomatina Recreation SA. Both projects require an annual return of 15 per cent. Year 0 1 Deepwater Fishing () -600000 270000 350000 300000 New Submarine Ride () -1800000 1000000 700000 900000 2 3 a) Show that the IRR for deepwater fishing it approximately 24.3%. b) Show that the IRR for the new submarine ride is approximately 21.46%. c) Which project should you choose based on IRR? d) Show that the incremental IRR (of the new submarine ride over deepwater fishing) is 19.92% e) If you were to use the NPV rule, which project would you choose? Is it consistent with the incremental IRR rule? 2)** [6-18] Suppose the following two independent one-off investment opportunities are available to Greenplain Ltd. The appropriate discount rate is 10 per cent. YEAR 0 1 2 3 Project Alpha (C) -550 320 720 600 Project Beta () -2,000 300 1,800 2,200 a) Compute the profitability index for each of the two projects. b) Which project(s) should Greenplain accept, based on the profitability index rule? c) Suppose that you could choose only one of the two projects, based on the NPV rule, which one would you choose? Is your choice consistent with the Profitability index? Can you reconcile the two results (one short sentence is sufficient)