Evaluate
\[\sum_{n = 0}^\infty \frac{\cos n \theta}{2^n},\]where $\cos \theta = \frac{1}{5}.$
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Evaluate
\[\sum_{n = 0}^\infty \frac{\cos n \theta}{2^n},\]where $\cos \theta = \frac{1}{5}.$
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\frac{6}{7}
Evaluate
\[\sum_{n = 0}^\infty \frac{\cos n \theta}{2^n},\]where $\cos \theta = \frac{1}{5}.$
train