IRR and ERR 1. Determine if the following cash flow is or isn't viable. Using IRR and ERR methods. The MARR is 10 percent. Also determine the Paybacks years. First Cost Annual Expense, S Annual Income, S Economic Life in Years Alternative-A 35,000 20,000 30,000 a. IRR ? b. ERR? c. Number of years for Simple Payback d. Number of years for Discount Payback