Question

Mike has his money in a savings account earning 3 percent interest. How long will it take for his money to double?

twelve years
two years
twenty-four years
eighteen years

Answer 1

By using 72 rule
72/rate=time
t=72÷3
t=24 years

Answer 2

After 24 years the money is doubled

Explanation:

Given that mike has his money in a savings account earning 3 percent interest.

we have to find in how much time the money is double.

Here we apply the rule of 72

72 rule is a simple rule to find how long an investment will take to double given fixed annual rate of interest.

By dividing 72 by the annual rate of return, we get the time i.e in how many years it will take the money to double.

`Time=\frac{72}{\text{interest percent}}=(72)/(3)=24 years`

Hence, the answer is 24 years.