<PRE><B>Question 986341</B>
Melanie drives into the city to buy some new shoes. With traffic she only averages 15mph. On the way home it&#39;s much clearer so she averaged 35mph. If the total travel time is 2 hours how long did it take her to get to the store?
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Avg speed of a round trip is:
2*R1*R2/(R1 + R2)
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Her avg speed is 2*15*35/(50) = 21 mi/hr
RT distance = 2*21 = 42 miles--&gt; 21 miles each way
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Time going = 21/15 = 7/3 hrs = 2 hr 20 minutes
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