Answer
$10^{-10}.$
Work Step by Step
We know that $a_n=a_1r^{n-1}.$
where $d$=common ratio and $a_1$= the first term
Here $a_1=1$ and $r=\frac{a_2}{a_1}=\dfrac{\frac{1}{10}}{1}=\frac{1}{10}$
Hence, here we have
$a_n=1(\frac{1}{10})^{n-1}.$
Therefore $a_{11}=1(\frac{1}{10})^{11-1}\\=\frac{1}{10^{10}}=10^{-10}.$
