Answer
Neither geometric not arithmetic
Work Step by Step
$\dfrac {1}{6}-\dfrac {1}{5}\neq \dfrac {1}{5}-\dfrac {1}{4}\neq \dfrac {1}{4}-\dfrac {1}{3}$
So this is not arithmetic sequence
$\dfrac {\dfrac {1}{6}}{\dfrac {1}{5}}\neq \dfrac {\dfrac {1}{5}}{\dfrac {1}{4}}\neq \dfrac {\dfrac {1}{4}}{\dfrac {1}{3}}$
Then this is not geometric sequence either
