Answer: the rate of the wind is 6.2 mph
Explanation:
Let x represent the rate of the wind.
Joe traveled against the wind in a small plane for 3hours. If the speed of the plane in still air is 180 mph, then the total speed with which the plane flew is
(180 - x) mph
Distance = speed × time
Therefore, distance travelled against the wind is
3(180 - x)
= 540 - 3x - - - - - - - - - - - - - -1
The return trip with the wind took 2.8 hours.
the total speed with which the plane flew is
(180 + x) mph
Therefore, distance travelled with the wind is
2.8(180 + x)
= 504 + 2.8x - - - - - - - - - - - - - -2
Since the distance is the same, then
540 - 3x = 504 + 2.8x
540 - 504 = 2.8x + 3x
5.8x = 36
x = 36/5.8 = 6.2