Answer: the speed of the train is 40 km/h
the speed of the plane is 180 km/h
Step-by-step explanation:
Let x represent the speed of the train.
If the speed of the plane is 20 km per hr less than 5 times the speed of the train, it means that the speed of the plane would be (5x - 20) km/h
Time = distance/speed
The train travels 200 km. This means that the time taken to travel 200 km is
200/x
in the same time that a plane covers 900 km. This means that the time taken to travel 900 km is
900/(5x - 20)
Since the time is the same, then
200/x = 900/(5x - 20)
Cross multiplying, it becomes
200(5x - 20) = 900x
1000x - 4000 = 900x
1000x - 900x = 4000
100x = 4000
x = 4000/100
x = 40
The speed of the plane would be
5 × 40 - 20
= 180
