# How do you tell whether the sequence #5, 10, 20, 40, 80, ...# is geometric?

##### 1 Answer

Mar 15, 2017

You can tell if

#### Explanation:

All these terms have a common ratio of 2. That means, if you take the next term up and divide it with the first term, you will always get this common ratio if it's a geometric series.

Since when you divide them, you always get the common ratio, that means the series is geometric.