Instructions: For each problem: identify input & output variables and include cash flow table; and identify method, solve problem on a separate Excel sheet using formula functions, and state answer in a sentence. Show all work 2. Two methods of carrying away surface runoff water from a new subdivision are being evaluated: Method A: Dig a ditch. The initial cost would be $40,000 and $15,000 of re-digging and shaping would be required at five-year intervals forever. Method B: Lay concrete pipe. The initial cost would be $60,000 and replacement pipe would be required at 40-year intervals at a net cost of $90,000, indefinitely. Justify which method is better at = 15%