D. interest on interest. ( E. compound interest. According to the Rule of 72, you can do which one of the following? A. Approximately double your money in five years at 7.24 percent interest B. Double your money in 7.2 years at 8 percent interest C. Approximately double your money in 11 years at 6.55 percent interest D. Triple your money in 7.2 years at 7.2 percent interest E. Approximately triple your money in 7.2 years at 10 percent interest