1. Rule of 72. Carla Martinez has saved 6,500. How long will it take for Carla’s savings to double if she is able to earn 4 percent a year? 2. Present Value of a Single Amount. Van Tran would like to...

1. Rule of 72. Carla Martinez has saved
6,500. How long will it take for Carla’s savings to double if she is able to earn 4 percent a year?

2. Present Value of a Single Amount. Van Tran would like to have
150,000 in his investment account in 20 years. He would like to invest a single sum that will grow to that goal at 4 percent a year. What amount should Van invest?