1. What is the total amount of interest for P=$30,020, n=11 years, and compound interest of 7% per year?

2. A rental company spent $9,600 on a new air compressor 10 years ago. The annual rental income from the compressor has been $1,130. In the first year, there was a $120 maintenance fee. The maintenance fee has increased each year by $30/year. What is the present worth at t = 0?

Hint: Use the net cash flow method in Excel will be easier.

3. At a compound interest rate of 9% per year, a person deposited an amount of $9,225 in a bank 9 years ago. What is the equivalent amount now?