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Question 207999: a plane flies 1,800 miles with the wind in 9 hours. the return trip takes 12 hours. what is the speed of the wind and the speed of the plane in still air?
? mph, speed of plane and ? mph speed of wind
Answer by nerdybill(7384)   (Show Source):
You can put this solution on YOUR website! a plane flies 1,800 miles with the wind in 9 hours. the return trip takes 12 hours. what is the speed of the wind and the speed of the plane in still air?
? mph, speed of plane and ? mph speed of wind
.
You will need to apply the "distance formula":
d = rt
where
d is distance
r is rate or speed
t is time
.
Let p = speed of plane
and w = speed of wind
.
From:"a plane flies 1,800 miles with the wind in 9 hours."
9(p+w) = 1800
p+w = 200 (equation 1)
.
From:"the return trip takes 12 hours."
12(p-w)=1800
p-w = 150 (equation 2)
.
Using the "addition method" let's add equation 1 to equation 2:
p+w = 200
p-w = 150
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2p = 350
p = 175 mph (speed of plane in still air)
.
Plug above into equation 1 and solve for w:
p+w = 200
175+w = 200
w = 25 mph (speed of wind)
.
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