SOLUTION: In the time it takes to fliy 360 miles with a head wind, she can only fly 240 mies against the headwind. if the speed of the plane in stll air is 150 mph, find the wind speed.

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: In the time it takes to fliy 360 miles with a head wind, she can only fly 240 mies against the headwind. if the speed of the plane in stll air is 150 mph, find the wind speed.      Log On


   



Question 139664: In the time it takes to fliy 360 miles with a head wind, she can only fly 240 mies against the headwind. if the speed of the plane in stll air is 150 mph, find the wind speed.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
In the time it takes to fly 360 miles with a head wind, she can only fly 240 mies against the headwind. if the speed of the plane in still air is 150 mph, find the wind speed.
:
Let x = the wind speed
then
(150-x) = ground speed against the wind
and
(150+x) = ground speed with the wind
:
write a time equation: Time = dist/speed
:
With time = Against time
360%2F%28%28150%2Bx%29%29 = 240%2F%28%28150-x%29%29
Cross multiply
240(150+x) = 360(150-x)
;
36000 + 240x = 54000 - 360x
:
240x + 360x = 54000 - 36000
:
600x = 18000
x = 18000%2F600
x = 30 mph is the wind speed
:
:
Check solution in original equation: Against speed = 120, With speed = 180
360%2F180 = 240%2F120; confirms our solution