document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=48348>Question 48348</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The Hudson River flows at a rate of 3 miles per hour.  A patrol boat travels 60 miles upriver, and returns in a total time of 9 hours.  What is the speed of the boat in still water? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #31979 by </B><A HREF=/tutors/aboutme.mpl?userid=venugopalramana><B>venugopalramana(3286)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=venugopalramana><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.geocities.com/venugopalramana/FREE_MATHS_ASSISTANCE.html valign=middle><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=31979\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The Hudson River flows at a rate of 3 miles per hour. A patrol boat travels 60 miles upriver, and returns in a total time of 9 hours. What is the speed of the boat in still water?<BR>\n" );
document.write( "let the boat speed in still water =b<BR>\n" );
document.write( "speed of water be =3<BR>\n" );
document.write( "speed up river =b-3..time to travel 60 miles=60/(b-3)<BR>\n" );
document.write( "speed down river =b+3..time to travel down river=60/(b+3)<BR>\n" );
document.write( "total time =60[{1/(b+3)}+{1/(b-3)}]=9<BR>\n" );
document.write( "60*(b+3+b-3)=9(b+3)(b-3)<BR>\n" );
document.write( "40b=3(b^2-9)=3b^2-27<BR>\n" );
document.write( "3b^2-40b-27=0<BR>\n" );
document.write( "b=13.978 mph </SPAN>\n" );
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