document.write( "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? \n" ); document.write( "
Algebra.Com's Answer #316085 by robertb(5830)\"\" \"About 
You can put this solution on YOUR website!
Get the harmonic mean of the two rates:\r
\n" ); document.write( "\n" ); document.write( "\"2%2F%281%2F10+%2B+1%2F30%29+=+15\"miles per hour, her average speed.
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