Answer:
The section of the path that has been built = 0.5 km.
Explanation:
The total length of the path to be built = 2.5 km
Let us assume the section of the path that has been built = s km
Now, 1/5 the of the path is build.
⇒ s = 1/5 the of the total path
Now,
⇒ s = 0.5 km
Hence, the section of the path that has been built = 0.5 km.