Two airplanes leave an airport at the same time, flying in the same direction. One plane is flying at twice the speed of the other. If after 4 hours they are 1800 km apart, find the speed of each plane.

The slower plane has a speed of 450 km/h and the faster one has a speed of 900 km/h.

Step-by-step explanation:

Two planes:

The first one's speed is x

The second is y.

One plane is flying at twice the speed of the other.

I will say that y = 2x.

Two airplanes leave an airport at the same time, flying in the same direction

Same direction, so their relative speed is the subtraction of their speeds. 2x - x = x.

Means that after 1 hour, they will be x miles apart.

If after 4 hours they are 1800 km apart, find the speed of each plane

After 1 hour, x km apart. After 4, 1800. So

1 hour - x km apart

4 hours - 1800 km apart

4x = 1800

x = 1800/4

x = 450

2x = 2*450 = 900

The slower plane has a speed of 450 km/h and the faster one has a speed of 900 km/h.