Answer:
15 miles
Step-by-step explanation:
Let
be the miles in the circular park path,
the time Louisa takes to finish and
the time Calvin takes to finish both in hours.
Then
, the longitude is equal to the velocity times the time used to finish. So


And the difference between Louisa's time and Calvin' time is 30 minutes, half an hour. So:

Three equations, three unknowns, the system can be solved.
Equalizing the equation with x :

In this last equation replace
with the other equation and solve:
With Louisa's time find x:
Use similar volume to calculate
which is the (ratio of edges)^3 = (ration of volume)
so just put the numbers in, let the volume of smaller pyramid be y.
(3/4)^3 = y/320
27/64 = y/320
y=135in3
<h2><em>JUST DO IT YOURSELF ITS BASIC FRACTIONS!!!!!!!!!</em></h2>