Question 710413
Wendy took a trip from city A to city B, a distance of 520 mi. She traveled part of the way by bus, which arrived at the train station just in time for Wendy to complete her journey by train. The bus averaged 40 mi/h, and the train averaged 60 mi/h. The entire trip took 10.5 hrs. How long did Wendy spend on the train?
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Train DATA:
distance = x miles ; rate = 60 mph ; time = x/60 hrs
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Bus DATA:
distance = 520-x miles ; rate = 40 mph ; time = (520-x)/40 hrs
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Equation: 
time + time = 10.5 hrs.
x/60 + (520-x)/40 = 10.5
Multiply thru by 120 to get:
2x + 3*520 - 3x = 120*10.5
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-x = -300
x = 300 miles:
train time = x/60 = 300/60 = 5 hours
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Cheers,
Stan H.