Question

Pearl deposited $60 into a savings account for which interest is compounded monthly. According to the rule of 72, what interest rate will cause her money to double in approximately 33 years?

A. 0.6%
B. 0.5%
C. 1.8%
D. 2.2%

Answer 1

@perl

Answer 2

so we can divide the given interest rates.
72 / .6
72/ .5
72/1.8
72/2.2

Answer 3

72/2.2 = 32.7272 ~ 33
so its D

Answer 4

oooooooooohhhhh ok thanks @perl