Answer
$\frac{3}{5}$ mile
Work Step by Step
Each side of the square is $\frac{3}{30}$ mile. There are four sides.
The perimeter therefore is:
$\frac{3}{20}+ \frac{3}{20} + \frac{3}{20} + \frac{3}{20}= \frac{12}{20}$
This can be simplified:
$\frac{12}{20}= \frac{4\times 3}{4\times5}= \frac{3}{5}$