SOLUTION: Maria drove to a business appointment at 50mph in the morning. Her average speed on the return trip in the afternoon was 40 mph. The return trip took 1/4hr longer because of traff

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Question 566220: Maria drove to a business appointment at 50mph in the morning. Her average speed on the return trip in the afternoon was 40 mph. The return trip took 1/4hr longer because of traffic. How far did she travel to the appointment?
Answer by Alan3354(69443) About Me  (Show Source):
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Maria drove to a business appointment at 50mph in the morning. Her average speed on the return trip in the afternoon was 40 mph. The return trip took 1/4hr longer because of traffic. How far did she travel to the appointment?
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d = r*t
d = 50t = 40*(t + 0.25)
50t = 40t + 10
t = 1 hour
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d = 50*1 = 50 miles
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Notice that the avg speed for the round trip is not the average of 50 and 40.
Why is that?
The avg speed is less, = 44.444... mi/hr, not 45