please do it with the easiest way.

QUESTION 3: a) You're trying to determine whether to expand your business by building a new manufacturing plant. The plant has an installation cost of $12 million, which will be depreciated straight-line to zero over its four-year life. If the plant has projected net income of $1,854,300,$1,907,600, $1,876,000 and $1,329,500 over these four years, what is the project's average accounting return (AAR)? b) A firm evaluates all its projects by applying the IRR rule. If the required return is 16 percent, should the firm accept the following project? c) What is the profitability index for the following set of cash flows if the relevant discount rate is 10 percent