a. (10) Based on a present worth analysis with an interest rate (MARR) of 6% what is the most economically attractive option? What is the present worth of each option over the analysis period?

b. (10) Calculate the incremental rate of return ?IRR for these two options. At a MARR of 6%, which of these two options is the most economically attractive option? Briefly explain why.

Initial cost Annual operating & maintenance cost Annual revenue Salvage value Useful life Option A $13000 $2000 $2500 $4000 12 years Option B $5000 $2000 $2500 $1000 4 years