SOLUTION: A train traveled 80 miles from city A to city B and returned the same distance in a total time of 6 hours. If the train traveled 20 mph slower on the return trip, how fast did the
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Question 350961: A train traveled 80 miles from city A to city B and returned the same distance in a total time of 6 hours. If the train traveled 20 mph slower on the return trip, how fast did the train travel in each direction? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A train traveled 80 miles from city A to city B and returned the same distance in a total time of 6 hours. If the train traveled 20 mph slower on the return trip, how fast did the train travel in each direction?
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A to B DATA:
distance = 80 miles ; rate = x mph ; time = 80/x hrs
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B to A DATA:
distance = 80 miles ; rate = x-20 mph ; time = 80/(x-20) hrs
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Equation:
time + time = 6 hrs
80/x + 80/(x-20) = 6
160x - 1600 = 6x(x-20)
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160x - 1600 = 6x^2 - 120x
6x^2 -280x + 1600 = 0
3x^2 - 140x + 800 = 0
(3x-20)(x-40) = 0
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Realistic Answer:
x = 40 mph (rate from A to B)
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x-20 = 20 mph (rate from B to A)
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Cheers,
Stan H.
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