document.write( "Question 114437: Rita rows 12 km upstream and 12 km downstream in 3 hours. The speed of her boat in still water is 9 km/hr. Find the speed of the stream \n" ); document.write( "
Algebra.Com's Answer #83252 by stanbon(75887)\"\" \"About 
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Rita rows 12 km upstream and 12 km downstream in 3 hours. The speed of her boat in still water is 9 km/hr. Find the speed of the stream
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\n" ); document.write( "Let speed of the stream be \"s\"
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\n" ); document.write( "Upstream DATA;
\n" ); document.write( "distance = 12 km ; Rate = 9-s km/h; Time = d/r = 12/(9-s) hrs.
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\n" ); document.write( "Downstream DATA:
\n" ); document.write( "distance = 12 km ; Rate = 9+s; Time = 12/(9+s) hrs.
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\n" ); document.write( "EQUATION:
\n" ); document.write( "time up + time down = 3 hrs
\n" ); document.write( "12/(9-s) + 12/(9+s) = 3
\n" ); document.write( "1/(9-s) + 1/(9+s) = 1/4
\n" ); document.write( "4(9+s) + 4(9-s) = 9^2-s^2
\n" ); document.write( "72 = 81-s^2
\n" ); document.write( "x^2 = 9
\n" ); document.write( "s = 3
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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