SOLUTION: A plane flies 500 miles with the wind and 340 miles against the wind in the same length of time. If the speed of the wind is 20 mph, what is the speed of the plane in still air?

Algebra ->  Equations -> SOLUTION: A plane flies 500 miles with the wind and 340 miles against the wind in the same length of time. If the speed of the wind is 20 mph, what is the speed of the plane in still air?      Log On


   

Question 1162617: A plane flies 500 miles with the wind and 340 miles against the wind in the same length of time. If the speed of the wind is 20 mph, what is the speed of the plane in still air?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Same amount of time, x
speed of plane without wind, r 
             SPEED       TIME       DISTANCE

WITH          r+20         x         500

AGAINST       r-20         x         340

500%2F%28r%2B20%29=340%2F%28r-20%29-------simplify and solve this.