Problems 1. You decide to make an investment. About how many years will it take to triple your investment at a 5% annual interest rate? (Ans. Approx. 23 years) 2. You have a credit card with an interest rate of 12% per year, compounded weekly. What is the annual effective interest rate? (Ans. 12.73%) 3. You would like a yearly annuity of $6,000 for 10 years at a 4% annual interest rate. How much do you need to invest initially to achieve this goal? (Ans. $48,665) 4. If $10,000 is borrowed now at 10% per year interest, how much will be the balance at the end of year 2 after payments of $3,000 in years 1 and 2? (Ans. $5,800) 5 If a company wants to have $100,000 in a contingency fund 10 years from now, how much should the company deposit each year in years 6 through 9, at interest rate of 10% per year? (Ans. $19,591)