document.write( "Question 425343: A train goes from boston to new york averaging 40 km per hour and returns averaging 60 km per hour. what is the average speed for the round trip? \n" ); document.write( "
Algebra.Com's Answer #296208 by ankor@dixie-net.com(22740)\"\" \"About 
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A train goes from boston to new york averaging 40 km per hour and returns averaging 60 km per hour. what is the average speed for the round trip?
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\n" ); document.write( "Let a = speed for the whole trip
\n" ); document.write( "let d = the one way distance
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\n" ); document.write( "Write a time equation, Time = dist/speed
\n" ); document.write( "from time + to time = total time
\n" ); document.write( "\"d%2F40\" + \"d%2F60\" = \"%282d%29%2Fa\"
\n" ); document.write( "Multiply by 120a, results
\n" ); document.write( "3ad + 2ad = 120(2d)
\n" ); document.write( "5ad = 240d
\n" ); document.write( "Divide both sides by d
\n" ); document.write( "5a = 240
\n" ); document.write( "a = \"240%2F5\"
\n" ); document.write( "a = 48 km/hr is the av for the round trip
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