It took x hours to set up, y hours to come back, and the total distance to go back and forth is z kilometers, so:

1、8x=6y

2、x+y= 10

3、Z=8x+6y

X=3y/4 can be obtained from the equation 1, and then x=30/7 and y=40/7 can be obtained by substituting it into equation 2.

Substituting X and Y into Equation 3, we can get Z=30/7×8+40/7×6=68.57 km.

This is junior high school math, right? I haven't written such a basic company for years, and I almost forgot all about it.