There are 50 sections.
Explanation:
Given,
Length of section = 10 meters
Total length of guardrail = 0.5 km
We will convert this length in meters.
1 km = 1000 meters
0.5 km = 0.5*1000 = 500 meters
Now,
No. of sections =

No. of sections =

No. of sections = 50
There are 50 sections.