No. This is not random sampling as the students chose are not chosen at random. Random sampling would be something done where each sample has equal probability of being chosen. Clearly this is not random sampling.
Answer:

Step-by-step explanation:

Answering from phone so this will be a bit messy.
a
b=a+1
c=b+1=a+2
2a=b+20
Therefore:
2a=a+1+20
a=21,b=22,c=23
Answer: The distance between Fort Collins and Greeley is 35.84 km.
Step-by-step explanation:
Since we have given that
Distance travelled due south of Fort Collins = 18 km
Distance traveled due west of Greeley = 31 km
So, using the pythagorous theorem, we will find the distance between Fort Collins and Greeley.
So, it becomes,

So, the distance between Fort Collins and Greeley is 35.84 km.