document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=109807>Question 109807</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a boat can go 60 mph in still water . it takesas long to go 560 miles upstream as it does to go downstream 640 miles. how fast is the current? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #79998 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=79998\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a boat can go 60 mph in still water . it takes as long to go 560 miles upstream as it does to go downstream 640 miles. how fast is the current?<BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "Let current speed be \"c\".<BR>\n" );
document.write( "Upstream DATA:<BR>\n" );
document.write( "Distance = 560 miles ;  Rate = (60-c) mph ; time = 560/(60-c) hrs<BR>\n" );
document.write( "---------------------------------<BR>\n" );
document.write( "Downstream DATA:<BR>\n" );
document.write( "Distance = 640 miles ;  Rate = (60+c) mph ; time = 640/(60+c) hrs<BR>\n" );
document.write( "-----------------------------------<BR>\n" );
document.write( "EQUATION:<BR>\n" );
document.write( "time = time<BR>\n" );
document.write( "560/(60-c) = 640/(60+c)<BR>\n" );
document.write( "7/(60-c) = 8/(60+c)<BR>\n" );
document.write( "420+7c = 480-8c<BR>\n" );
document.write( "15c = 60<BR>\n" );
document.write( "c = 4 mph (current speed)<BR>\n" );
document.write( "===============<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );