SOLUTION: a girl rides her bike up a hill at 10 miles per hour. She then rides her bike down the hill at 30 miles per hour. What is her average speed for the round trip?

SOLUTION: a girl rides her bike up a hill at 10 miles per hour. She then rides her bike down the hill at 30 miles per hour. What is her average speed for the round trip?

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Question 460813: a girl rides her bike up a hill at 10 miles per hour. She then rides her bike down the hill at 30 miles per hour. What is her average speed for the round trip?
Answer by robertb(5830) (Show Source): You can put this solution on YOUR website!
Get the harmonic mean of the two rates:
miles per hour, her average speed.
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