document.write( "Question 114152: In still water , Larry sails his boat at an average of 30km/h. One day, he spent as much time sailing 104km down river as he did sailing 91km back up the river. What was the rate of the river current ? \n" ); document.write( "
Algebra.Com's Answer #83072 by stanbon(75887)\"\" \"About 
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In still water , Larry sails his boat at an average of 30km/h. One day, he spent as much time sailing 104km down river as he did sailing 91km back up the river. What was the rate of the river current ?
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\n" ); document.write( "Let current rate be \"c\"
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\n" ); document.write( "Down River DATA:
\n" ); document.write( "Distance = 104 km ; Rate = (30+c) km/h ; Time = 104/(30+c) hrs
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\n" ); document.write( "Up River DATA:
\n" ); document.write( "Distance = 91 km ; Rate = (30-c) km/h ; Time = 91/(30-c) hrs
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\n" ); document.write( "EQUATION:
\n" ); document.write( "time up = time down
\n" ); document.write( "91/(30-c) = 104/(30+c)
\n" ); document.write( "104(30-c) = 91(30+c)
\n" ); document.write( "3120-104c = 2730+91c
\n" ); document.write( "195c = 390
\n" ); document.write( "c = 2 km/h (speed of the current)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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