Compound Interest
When Jack turned 21, he decided to start investing $200 a month every year for nine years. At age 30, he decided to stop investing altogether.
Blake started a little later, investing $200 a month every month starting at age 30, all the way until the ripe old age of 67.
Assuming that they were both amazing at investing and made 11% interest per year, how much money will they both have at age 67?