document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=426820>Question 426820</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boat goes upstream 600 m, moving 30 m/min through the water. The boat travels back downstream to the starting point, this time only going 20 m/min through the water. The total time spent is 75 minutes. How fast was the current flowing? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #297159 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=297159\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A boat goes upstream 600 m, moving 30 m/min through the water. The boat travels back downstream to the starting point, this time only going 20 m/min through the water. The total time spent is 75 minutes. How fast was the current flowing?<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "b = boat's speed relative to the water<BR>\n" );
document.write( "c = current<BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "Upstream  + downstream = 75 mins<BR>\n" );
document.write( "600/(30 - c) + 600/(20 + c) = 75<BR>\n" );
document.write( "One equation and one variable<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=600%2820%2Bc%29+%2B+600%2830-c%29+=+75%2820%2Bc%29%2830-c%29+=+75%28600%2B10c-c%5E2%29 ALIGN=MIDDLE  ALT=\"600%2820%2Bc%29+%2B+600%2830-c%29+=+75%2820%2Bc%29%2830-c%29+=+75%28600%2B10c-c%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8%2820%2Bc%29+%2B+8%2830-c%29+=+%28600%2B10c-c%5E2%29 ALIGN=MIDDLE  ALT=\"8%2820%2Bc%29+%2B+8%2830-c%29+=+%28600%2B10c-c%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=160+%2B+240+=+%28600%2B10c-c%5E2%29 ALIGN=MIDDLE  ALT=\"160+%2B+240+=+%28600%2B10c-c%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c%5E2+-+10c+-+200+=+0 ALIGN=MIDDLE  ALT=\"c%5E2+-+10c+-+200+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(c-20)*(c+10) = 0<BR>\n" );
document.write( "c = 20 m/min </SPAN>\n" );
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