# How do you calculate to the nearest hundredth of a year how long it takes for an amount of money to double if interest is compounded continuously at 3.8%?

##### 1 Answer

Mar 29, 2015

This is an example of an exponential function.

These are allways of the form

Where

With an interest rate of 3.8%, your growth factor will be:

To double your money the ratio of

So

Two ways to solve this:

**By logs:**

**By GC:**

**Extra** :

You could even say it would be on day 215 of the 19th year, but that was not the question.