I’m pretty sure the answers are:
250 meters=0.25 kilometers
12 meters=0.012 kilometers
1 meter=0.001
5 kilometers=5,000 meters
20 kilometers=20,000 meters
0.3 kilometers=300 meters
For future reference, you can find the constant of proportionality by dividing the x value by the y value. Then you multiply each given number by the constant of proportionality, and that’ll give you your answers.
Unfortunately, I don’t know the answers to the last few questions. Sorry about that!