# What is the eighth term of the geometric sequence whose first three terms are 3, 6 and 12?

Jan 12, 2016

First, calculate the common ratio $r$ ...

#### Explanation:

$r = \frac{6}{3} = 2$

Using the formula for the nth term of a geometric sequence ...

${a}_{n} = {a}_{1} {\left(r\right)}^{n - 1}$

${a}_{8} = 3 {\left(2\right)}^{\left(8 - 1\right)} = 3 \times {\left(2\right)}^{7} = 384$

hope that helped