Answer:
23% im pretty sure that is the answer if i remember right
Answer: 0.69 m/ mile.
Explanation:
The altitude gradient between two cities X and Y = 
Given: Two cities are separated by 200 miles.
City X has an altitude of 122 meters.
City Y has an altitude of 260 meters.
The altitude gradient between two cities X and Y =

Hence, the altitude gradient between the two cites = 0.69 m/ mile.