Problem #11: Suppose that you invest $3000 at an annual interest rate of 5%, compounded continuously. How long will it take (in years) for your money to (a) double? (b) triple? Problem #12: Suppose that you want to purchase a used car for $7000. You currently have $3000. If you invest your $3000 at an annual interest rate of 3%, compounded semiannually, how long will it take (in years) before you can purchase the car? Problem #12: Round your answer to 2 decimals.