Colette opened a CD 10 years ago at an interest rate of 8.8%, compounded quarterly. According to the rule of 72, when did she have half the amount of money that she has now?

A. About 4.4 years ago
B. About 8.2 years ago
C. About 4.1 years ago
D. About 8.8 years ago

Question

Colette opened a CD 10 years ago at an interest rate of 8.8%, compounded quarterly. According to the rule of 72, when did she have half the amount of money that she has now?

 		A.	About 4.4 years ago
 		B.	About 8.2 years ago
 		C.	About 4.1 years ago
 		D.	About 8.8 years ago

anonymous · Answer

@perl

anonymous · Answer

did ya look it up?

anonymous · Answer

yes @tyga24

anonymous · Answer

hold up wait a min k?

perl · Answer

it should be 8.2 years ago, you are using rule of 72 in reverse

anonymous · Answer

how many Q's r there

perl · Answer

right now you have double the amount of money you had  when you had half the amount

anonymous · Answer

ok @tyga24

perl · Answer

so for example, suppose you have 10,000 dollars now, how long ago did you have 5,000 dollars? Well, that's the same thing as asking, starting from 5,000 dollars, how long will it take to get to 10,000 dollars (doubling the amount). to double money at 8.8% interest it takes 72/8.8

perl · Answer

it takes 72/8.8 years to double your money at 8.8% annual interest

anonymous · Answer

tbh idk it but check out this link http://ftpmirror.your.org/pub/wikimedia/images/wikipedia/commons/0/0b/Guide_of_whetevert_2.pdf

anonymous · Answer

thanks @perl  and @tyga24

perl · Answer

@tyga24  nice link, where did you get that?

anonymous · Answer

i know my way around the internet ;)