A B747 aircraft flew 6 hours with the wind The return trip t

A B747 aircraft flew 6 hours with the wind. The return trip took 7 hours against the wind. If the speed of the plane in still air is 13 times the speed of the wind, find the wind speed and the speed of the plane in still air.

Solution

Let x = speed of the wind
then
13x = speed of the plane in still air
then
12x = speed against the wind
and
14x = speed with the wind
:
Distance of the trips are equal so write a dist equation: dist = time * speed
:
7(12x) = 6(14x)
84x = 84x like you would expect, just pick a speed for wind
Say 40 mph
then
13*40 = 520 mph is the plane in still air, sounds reasonable, other speeds will work too