Chapter R.1, Problem 42E

What interest rate would you need to get to double an investment of 200 in eight years?

To get the best loan rates available, the Riches want to save enough money to place 20% down on a $160,000 home. They plan to make monthly deposits of $125 in an investment account that offers 8.5% annual interest compounded semiannually. Will the Riches have enough for a 20% down payment after five years of saving? How much money will they have saved?

Rachael deposits $1500 into a retirement fund each year. The fund earns 8.2% annual interest, compounded monthly. If she opened her account when she was 19 years old, how much will she have by the time she is 55? How much of that amount will be interest earned?