need excel functions please

A new plan to produce steel tubing requires an initial investment of $87 million. It is expected that an additional investment of $ 6 million in year 3 and an investment of $ 4 million in year 6. Annual operating cost will be $ 2.7 million. The Annual revenues will be $ 49 million which is expected to increase by 2.5% every year. The life of the plant is 10 years. If the interest rate is 15% per year. Determine the NPV of this project. What is the Discounted Payback period