Calcuate NPV of insulation decision when cost of fuel is increasing

Category: Economics
Subject: Net Present Value
Details: It costs $2600 to insulate a factory. Nest year, the fuel savings will be $220. EAch year after this, the cost of fuel is expected to rise by the rate g. If the discount rate is 12%, what rate of growth in fuel costs justifies going ahead with the insulation plan? (Hint: careul. Make sure that the rate of growth and the discount rate are aligned in terms of periodss.)