Answer
$81:1$
Work Step by Step
The given values are
$r_l=27\;in.$
$r_s=3\;in.$
Formula for the mechanical advantage is
$\Rightarrow MA=\frac{r_l^2}{r_s^2}$
Substitute all the values.
$\Rightarrow MA=\frac{(27\;in.)^2}{(3\;in.)^2}$
Cross multiply.
$\Rightarrow MA=\frac{81}{1}$
Hence, the $MA$ is $81:1$.