Question

If you earn a 4% annual return on your retirement account each year, how long will it take the current account balance to double if you don't make any additional deposits to the account?

	A.	9 years
	B.	18 years
	C.	36 years
	D.	72 years

Answer 1

Option B. 18 years

Explanation: According to the rule of 72, we can find out the number of years required to double a particular amount at a given interest rate using the following formula:

The number of years = 72/rate of interest.

So, here the number of years = 72/4 = 18 years.