Answer:
 5 hours
Step-by-step explanation:
The rental option for h hours costs ...
 r = 30h
The purchase option for h hours costs ...
 p = 125 +5h
These costs are the same when ...
 r = p
 30h = 125 +5h
 25h = 125 . . . . . subtract 5h
 h = 5 . . . . . . . . . divide by 25
Karrisa must ski for 5 hours for the prices to be the same.