in 5 hours they are 2000 miles apart. so in one hour they have to be 400miles apart.
x>y, y=x-40
x+y=400
2x-40=400
x=220miles per hour
the slower plane goes at 220-40=180mph!
2007-03-20 04:27:01
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answer #1
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answered by xyz 1
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use the rt = d formula to work this problem.
Let r = rate of the slower plane.
r + 40 = rate of the faster plane
5 hours = time the planes fly
2000 = total distance for the two planes.
5r = distance of the slower plane
5(r + 40) = distance the faster plane
5r + 5(r + 40) = 2000
5r + 5r + 200 = 2000
10r + 200 = 2000
10r = 1800
r = 180 mph
2007-03-20 04:27:12
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answer #2
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answered by Ray 5
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If the slower plane is traveling at a speed v, then the faster one is traveling at v + 40 in the opposite direction. Each hour, the distance between them increases by the sum of those speeds, or 2v + 40. So we have
5(2v + 40) = 2000
10v + 200 = 2000
10v = 1800
v = 180, the speed of the slower plane.
2007-03-20 04:24:45
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answer #3
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answered by DavidK93 7
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Plane 1: speed = (x + 40) mph
Plane 2: speed = x mph
D1 = 5.(x + 40) = 5x + 200
D2 = 5x
5x + 5x + 200 = 2000
10x = 1800
x = 180
Rate of slower plane = 180 mph
2007-03-20 08:31:14
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answer #4
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answered by Como 7
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the slower plane is 180mph, the faster one is 220mph, their difference is 4omph.
First divide 2000 by 5, so it'll be 400 mph.
You mentioned their difference of 40mph, so let x be the slower plane, and x+40 be the faster plane.
In an hour, you have:
x + (x+40) = 400
2x = 400 - 40
x = 180
So, x (slower) = 180 mph
x + 40 (faster) = 220 mph
2007-03-20 04:32:29
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answer #5
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answered by DJ 3
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let v be velocity of slower plane
w - velocity of faster plane
we're told that
w = v + 40, and
(w+v) * 5 = 2000
substitute w = v+40
(v+40+v)*5=2000
2v+40=400
2v=360
v=180
then, w=180+40=220
2007-03-20 04:23:34
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answer #6
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answered by iluxa 5
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