Mack opened a CD 10 years ago at an interest rate of 7.8% compounded monthly. According to the rule of 72, when did she have half as much money as she does now?
A. About 9.2 years ago
B. About 4.6 years ago
C. About 3.9 years ago
D. About 7.8 years ago
9.2 years agoposted by Anonymous