You currently spend $6,000 to hire workers for maintaining the pool in your home. You are planning to buy some equipment to automate the maintenance process. These equipment will result in savings of $1,000 per year for the next 10 years. Assume no taxes and discount rate to be 10%. Show your work in excel.

a) If the system costs $7,000 to install, what is the NPV of purchasing the new equipment?

b) If your answer to part a is negative, what additional savings per year is required for you to change your decision?