SOLUTION: an airplane travels 900 miles from houston to miami in 6 hors against the wind.on its return trip, with the wind, it takes only 5 hours. find the rate of the airplane with no wind.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: an airplane travels 900 miles from houston to miami in 6 hors against the wind.on its return trip, with the wind, it takes only 5 hours. find the rate of the airplane with no wind.      Log On


   



Question 264864: an airplane travels 900 miles from houston to miami in 6 hors against the wind.on its return trip, with the wind, it takes only 5 hours. find the rate of the airplane with no wind. find the rate of the wind
Found 2 solutions by mananth, ikleyn:
Answer by mananth(16949) About Me  (Show Source):
You can put this solution on YOUR website!
an airplane travels 900 miles from houston to miami in 6 hors against the wind.on its return trip, with the wind, it takes only 5 hours. find the rate of the airplane with no wind. find the rate of the wind
Let the ground speed be x
And the wind speed be y
AGAINST WIND
Distance = 900 miles.
Distance = Rate * time
900= (x-y)*6
WITH WIND
Distance = 900 miles.
Distance = Rate * time
900= (x+y)*5
6x-6y=900
x-y= 150
5x+5y=900
x+y=180
x-y= 150
x+y=180
2x=330
x= 165 mph = ground speed ( With no wind )
y= 15
The ground speed of the plane is 165 mph and wind speed = 15 mph






Answer by ikleyn(53751) About Me  (Show Source):
You can put this solution on YOUR website!
.
an airplane travels 900 miles from Houston to Miami in 6 hors against the wind.
on its return trip, with the wind, it takes only 5 hours.
find the rate of the airplane with no wind. find the rate of the wind
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        The solution in the post by @mananth is correct: it leads to correct answer.
        But the @Mananth' solution is badly organized.

        One of the goals of such problems is to teach students to present their solution in perfect
        form with straightforward logic.

        Therefore I place my solution here.


Let the ground speed be x
And the wind   speed be y


AGAINST WIND

Distance = 900 miles.
Rate = Distance/time
x-y = 900/6 = 150 miles per hour.


WITH WIND

Distance = 900 miles.
Rate = Distance/time
x + y = 900/5 = 180  miles per hour.


Thus we have a system of two equations for unknowns x and y

    x - y = 150    (1)
    x + y = 180    (2)


To find 'x', add the equations.  You will get

    2x = 150 + 180 = 330  --->  x = 330/2 = 165.


To find 'y', substitute x = 165 in equation (2)

    165 + y = 180  --->  y = 180 - 165 = 15.


ANSWER.  The rate of the plane with no wind is 165 miles per hour.

         The rate of the wind is 15 miles per hour.

Solved.