If you insulate your office for $1,000, you will save $100 a year in heating expenses. These savings will last forever. a. What is the NPV of the investment when the cost of capital is 8%? (Round your answer to the nearest cent.) NPV $ 250 What is the NPV of the investment when the cost of capital is 10%? (Round your answer to the nearest cent.) NPV b. What is the IRR of the investment? (Round your answer to 2 decimal places.) IRR 10 % c. What is the payback period on this investment? (Round your answer to 2 decimal places.) Payback period 10 years d. What is the discounted payback period on this investment when the cost of capital is 8%? (Round your answer to 2 decimal places. If there is no finite discounted payback period, enter "0" as the answer to the question.) Discounted payback period years