SOLUTION: Flying against the wind, an airplane travels 3240 km in 6 hours. Flying with the wind, the same plane travels 8160 km in 8 hours. What is the rate of the plane in still air and wha

Let u = airplane speed at no wind and v = the wind speed.

Then

 = 540 is effective speed against the wind, which is the difference u-v:

u - v = 540      (1)


 = 1020 is effective speed with the wind, which is the sum u+v:

u + v = 1020     (2)


Add equations (1) and (2) to get

2u = 1560  ====>  u =  = 780 km/h  is the airplane speed at no wind.


Then from (1)  v = 1020 - 780 = 240 km/h  for the wind.


This result for the wind TELL you that the problem is very BADLY DESIGNED, because 240 km/h is more than an hurricane speed 
and any flights are prohibited under such conditions.


I don't like very much to work with badly designed problems.


My personal opinion is that their creators deserve a punishment.