Then the average speed of the plane is 8 kilometers per hour.
Train running 1050km takes (1050/x) hours.
It takes (1050km) hours for the plane to run 1050/(8x).
According to the meaning of the question, list the equations:
1050/(8x) =1050/x-8 and 3/4.
Solution: x= 105
8x=840
So the average speed of the train:105 km/h.
Average speed of aircraft: 840 km/h.