A local bank is running the following advertisement in the newspaper: "For just $1,000 we will pay you $100 forever!" The fine print in the ad says that for a $1,000 deposit, the bank will pay $100 every year in perpetuity, starting one year after the deposit is made. What interest rate is the bank advertising (what is the rate of return of this investment)?

Part 1

The interest rate the bank is advertising is