Question

If a plane can travel 460 miles per hour with the wind and 420 miles per hour against the wind, what is the speed of the wind and the speed of the plane in still air?

Answer 1

`440` mph

Explanation:

If `v_p` is the speed of the plane in still air, and `v_w` is the speed of the wind, then

`v_p+v_w = 460` and
`v_p-v_w = 420`

`2v_p = 880`

`:. v_p = 440`