Question 560195
The local train is 25 miles down the track from central station when the express leaves the station.
 The local train travels at a rate of 50 mi/hr and the express travels at a rate of 80 mi/hr.
 Let N represent the number of hours since the express train left Central Station.
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Question 1.) Write at expression that represents the express train's distance from Central Station in N hours.
80n
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Question 2.) When will the express train catch up with the local train?
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When the express catches up with the local, they will have traveled the same distance
write a distance equation: dist = = speed * time
:
80n = 50(n + {{{50/25}}}) 
80n = 50(n+.5)
80n = 50n + 25
80n - 50n = 25
30n = 25
n = {{{25/30}}}
n = {{{5/6}}} hr or 50 minutes to catch up with the local
:
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Confirm this by finding the actual distances, they should be the same:
Local took half hr longer; 8/6 hrs
{{{5/6}}}*80 = 66.67 mi
{{{8/6}}}*50 = 66,67 mi