Answer:
2000/17 = 117 11/17 miles
Explanation:
You want to know the number of miles of a 250-mile trip that are not downhill if 9/17 of the trip is downhill.
Fraction
The fraction that is not downhill is the difference between the fraction representing the whole trip, and the fraction that is downhill:

Miles
That fraction of the total trip miles is ...
(8/17) · (250 mi) = (8·250)/17 mi = 2000/17 mi = 117 11/17 mi
The number of miles not downhill was 2000/17 or 117 11/17 miles.