SOLUTION: Ian is standing 1.4 miles across a 2 mile railroad bridge when he sees a train approaching at a constant speed. Astonishingly enough, he can just get off the bridge by either runni

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Question 420509: Ian is standing 1.4 miles across a 2 mile railroad bridge when he sees a train approaching at a constant speed. Astonishingly enough, he can just get off the bridge by either running toward or away from the train at his constant speed of running. Find the number of miles that the train is from the bridge when Ian sees the train. (d=rt)
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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Ian is standing 1.4 miles across a 2 mile railroad bridge when he sees a train approaching at a constant speed.
Astonishingly enough, he can just get off the bridge by either running toward
or away from the train at his constant speed of running.
Find the number of miles that the train is from the bridge when Ian sees the train. (d=rt)
:
Assume he is .6 mi from end of the bridge where the train enters and
1.4 mi from the opposite end.
:
The train will enter the bridge when he has traveled .6 mi, going toward the
opposite end of the bridge, he will be .6 + .6 = 1.2 mi from the train when
it enters the bridge.
We can say that he travels .8 mi while the train travels 2 mi, to the end of the bridge.
:
Let d = distance train is from the bridge when he see's the train
Train travels d miles while he travels .6 mi
Using a ratio equation
.6%2Fd = .8%2F2
.8d * .6 * 2
.8d = 1.2
d = 1.2%2F.8
d = 1.5 mi from the bridge