SOLUTION: Hi Dear Tutor I need your help to explain to me how we put this word problem into a equation. I tried here but i dont think i m getting the right answer, plus my book does not have

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Question 603093: Hi Dear Tutor I need your help to explain to me how we put this word problem into a equation. I tried here but i dont think i m getting the right answer, plus my book does not have a similiar example. You dont have to give me the answer but if you could show me how to make the equation with this information.
Thank You very much,
Monick

1)A plane traveled 630 miles to Tokyo and back. The trip there was with the wind.It took 7 hours. The trip back was into the wind. The trip back took 21 hours. What is the speed of a plane in still air? what is the speed of the wind?
Found 3 solutions by Alan3354, stanbon, lwsshak3:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website!
1)A plane traveled 630 miles to Tokyo and back. The trip there was with the wind.It took 7 hours. The trip back was into the wind. The trip back took 21 hours. What is the speed of a plane in still air? what is the speed of the wind?
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Find the 2 groundspeeds.
with the wind, 630/7 = 90 mi/hr (some plane)
against the wind, 630/21 = 30 mi/hr
The plane's airspeed is the average: (90 + 30)/2 = 60 mi/hr
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The windspeed is the difference: 90 - 60 = 30 mi/hr
Shoulda taken a bus.

Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website!
A plane traveled 630 miles to Tokyo and back. The trip there was with the wind.It took 7 hours. The trip back was into the wind. The trip back took 21 hours. What is the speed of a plane in still air? what is the speed of the wind?
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To-Tokyo DATA:
distance = 630 ; time = 7 hrs ;rate would be 90 mph
Note: That data doesn't make any sense for an airplane.
It's even less sensible if it takes 21 hrs to return from
Tokyo.
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Cheers,
Stan H.

Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website!
1)A plane traveled 630 miles to Tokyo and back. The trip there was with the wind.It took 7 hours. The trip back was into the wind. The trip back took 21 hours. What is the speed of a plane in still air? what is the speed of the wind?
**
let x=speed of plane in still air
let c=speed of wind
(x+c)=net speed of plane with wind
(x-c)=net speed of plane into wind
distance=travel time*speed
..
7(x+c)=630
21(x-c)=630
..
7x+7c=630
21x-21c=630
..
21x+21c=1890
21x-21c=630
add, eliminating c
42x=2520
x=2520/70=60
7c=630-7x=630-420=210
c=30
..
ans:
speed of plane in still air=60 mph
speed of wind=30 mph
..
50 mph for plane speed seems a bit slow for this type of problem