Wendy took a trip from Davenport to Omaha a distance of 300

Wendy took a trip from Davenport to Omaha, a distance of 300 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 40mi/h and the train 60mi/h. The entire trip took 5 1/2h. How long did Wendy spend on the train?

Solution

Let b = bus time, abd Let t = train time
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distance = velocity * time
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40 * b + 60 * t = 300
and b + t = 5.5,,,,, or b = 5.5 -t
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40 ( 5.5 -t) + 60 t = 300
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220 -40t +60t = 300
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20t = 80
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t=4 hrs
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b= 5.5-4 = 1.5 hrs
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check
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40(1.5) + 60(4) = 300
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60 + 240 = 300,,,,,ok