1. Robin invests $8,000 at 6% interest compound annually. How much will he have after 4 years?

2. Sara wants to have $500,000, 10 years from now. How much should she invest now if she supposes to receive a return on her investment of 8% per year?

3. You gave loan of 50,000 baht to your friend for which your friend will repay 70,130 baht at the end of year 5. What is the interest rate you are charging your friend?