Question

Two planes left an airport at noon. One flew east at a certain speed and the other flew west at twice the speed. The planes were 2700 mi apart in 3 h. How fast was each plane flying?

Answer 1

If we call the speed of the first plane `v` then the other plane has a speed of `2*v`

Explanation:

So the distance between the planes will get greater by
`v+2*v=3*v` every hour
So in three hours their distance will be:
`3*3*v` which is equal to `2700mi`

So `9*v=2700->v=2700/9=300mph`
And the other plane had twice that speed: `600mph`