Answer
The sequence is not geometric.
Work Step by Step
In order to determine whether or not a sequence is geometric, we need to find out if there is a common ratio, $r$, between the terms:
$r = \frac{10}{5} = 2$
$r = \frac{15}{10} = \frac{3}{2}$
The ratios between the terms are different; therefore, there is no common ratio. The sequence is not geometric.
