Answer
Geometric with $r=\frac{1}{3}$
Work Step by Step
$270, 90, 30, 10, \frac{10}{3} ,\frac{10}{9} , . . .$
$\frac{a_2}{a_1}=\frac{90}{270}=\frac{1}{3}=r$
$ra_2=30=a_3$
$ra_3=10=a_4$
$ra_4=\frac{10}{3}=a_5$
and so on. The sequence is geometric with common ratio $r=\frac{1}{3}$.