SOLUTION: An airplane can go 900 miles with the wind in the same time that it can go 720 miles against the wind. IF the wind rate it 15mph, what is the rate of the airplane in still air?

Algebra ->  Test -> SOLUTION: An airplane can go 900 miles with the wind in the same time that it can go 720 miles against the wind. IF the wind rate it 15mph, what is the rate of the airplane in still air?      Log On


   



Question 638571: An airplane can go 900 miles with the wind in the same time that it can go 720 miles against the wind. IF the wind rate it 15mph, what is the rate of the airplane in still air?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Plane speed x mph
wind speed 15 mph
..
against wind x - 15 mph
with wind x + 15 mph

Distance against wind 720
Distance with wind 900
Time = same equate the time against with time with current
t=d/r
720 /(x- 15 )= 900 /(x+ 15 )
720 *(x+ 15 )= 900 *(x- 15 )
720 x + 10800 = 900 x -13500
720 x -900 x = -13500 + -10800
-180 x = -24300
/ -180
x= 135 mph
m.ananth@hotmail.ca