Answer
$25:1$
Work Step by Step
The given values are
$r_l=15\;in.$
$r_s=3\;in.$
Formula for the mechanical advantage is
$\Rightarrow MA=\frac{r^2_l}{r^2_s}$
Substitute all the values.
$\Rightarrow MA=\frac{15^2_l}{3^2_s}$
Cross multiply.
$\Rightarrow MA=\frac{25}{1}$
Hence, the $MA$ is $25:1$.
