SOLUTION: In Canada, eastbound and westbound trains travel along the same track, with sidings to pull onto to avoid accidents. Two trains are now 150 miles apart, with the westbound train

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: In Canada, eastbound and westbound trains travel along the same track, with sidings to pull onto to avoid accidents. Two trains are now 150 miles apart, with the westbound train      Log On


   

Question 1187700: In Canada, eastbound and westbound trains travel
along the same track, with sidings to pull onto to
avoid accidents. Two trains are now 150 miles apart,
with the westbound train traveling twice as fast as
the eastbound train. A warning must be issued to pu
one train onto a siding, or else the trains will crash in
1-1/4 hours. Find the speed of the eastbound train and
the speed of the westbound train.
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
Two trains are now 150 miles apart,
So Distance = 150
the westbound train traveling twice as fast as
the eastbound train.
So let the eastbound train's rate is r.
Then the westbound train's rate is 2r.
Their approach rate is the sum of their rates, 3r
So RATE+=+3r
the trains will crash in 1-1/4 hours.
So TIME+=+1%261%2F4
DISTANCE = (RATE)(TIME)
    125+=+%283r%29%281%261%2F4%29
    125+=+%283r%29%285%2F4%29
    125+=+15r%2F4
    500+=+15r
    33%261%2F3+=+r

The eastbound train's speed = r = 33 1/3 mph
The westbound train's speed = 3r = 100 mph 
 
Edwin