Answer
$\log_{\frac{1}{3}}{(\frac{1}{27})}=3$
Work Step by Step
RECALL:
$y=a^b \longleftrightarrow \log_a{y}=b$
Use the definition above to have
$\left(\frac{1}{3}\right)^{3}=\frac{1}{27} \longleftrightarrow \log_{\frac{1}{3}}{(\frac{1}{27})}=3.$