SOLUTION: A plane can fly 255 miles downwind in the same amount of time as it can travel 165 miles upwind. Find the velocity of the wind if the plane can fly 210 mph in still air.

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A plane can fly 255 miles downwind in the same amount of time as it can travel 165 miles upwind. Find the velocity of the wind if the plane can fly 210 mph in still air.      Log On


   

Question 1143008: A plane can fly 255 miles downwind in the same amount of time as it can travel 165 miles upwind. Find the velocity of the wind if the plane can fly 210 mph in still air.
Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!


Let  w = wind speed





(1)  (210 + w)t = 255  --->   210t + wt = 255   --->  wt = 255-210t

(2)  (210 - w)t = 165  --->   210t - wt = 165 



Subs for wt (rightmost derivation of eq (1)) into (2):



   210t - (255-210t) = 165

   420t = 420  

      t = 1hr  --> (using (1)) --> (210+w)(1) = 255 -->  +highlight%28w+=+45%29+ mi/hr