Solution:
Given:
The distance Wayne computed is;

Therefore, the distance Wayne computed is 35 miles.
If Wayne travels directly from Ferris to Butte;

Therefore, the distance if Wayne travels directly from Ferris to Butte is 25 miles.
The distance if Wayne travels directly is shorter than the distance Wayne found.
It is shorter by;

Therefore, it is shorter by 10 miles if Wayne travels directly from Ferris to Butte.