9. You are recommending installation of solar panels at a cost of $15,000 to your boss at the construction site. How should you define the potential benefits that you need to receive to justify the investment?

10. You want to buy a house and figure the best down payment would be $30,000. You can save $400 every month. If these monthly payments earn an annual rate of 9%, how many months will it take you to get your down payment?

***These are not related questions***