Flying against the wind, an airplane travels 3850 km in 7 hours. Flying with the wind, the same plane travels 4350 km in 5 hours. What is the rate of the plane in still air and what is the rate of the wind?

Guest Mar 21, 2020

#1**+1 **

Flying against the wind, an airplane travels 3850 km in 7 hours. Flying with the wind, the same plane travels 4350 km in 5 hours. What is the rate of the plane in still air and what is the rate of the wind?

Let P be the plane's rate in still air

Let the rate of the wind = W

So we have that Time * Rate = Distance

So

7(P - W) = 3850 divide both sides by 7

5(P + W) = 4350 divide both sides by 5

P - W = 550

P + W = 870 add these

2P = 1420 divide both sides by 2

P = 710 (kph)

And

710 - W = 550

W = 710 - 550

W = 160 [kph]

That's a STRONG WIND !!!!

CPhill Mar 21, 2020

#2**+2 **

LOL!!!!!!! Anyway, here's another way to do it.

x=Plane's rate in still air

y= Rate of the wind

x-y=550

x+y=870

Then, use the elimination method. (subtract)

-2y=-320

y=160km/h

Then, we know that the plane's rate in still air is 550+160, which is 710 km/h.

It is DEFINITELY A STRONG WIND!!!!!!!

CalTheGreat
Mar 21, 2020