can someone help with this?

7-15 For the following diagram, compute the IRR to within1/2%. 7-22 Compute the rate of return for the following cash flow. For the following diagram, compute the rate of return. A firm is considering two alternatives that have no salvage value. At the end of 4 years, another B may be purchased with the same cost, benefits, and so forth. Construct a choice table for interest rate from 0% to 100%. If the MARR is 10%, which alternative should be selected