document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=766123>Question 766123</A>: <I><SPAN STYLE=\"word-break: break-all;\"> speed of water in certain river is 6kmph and it takes a boat four times as long to row up as to row down the river. what is the speed of boat in still water?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #466675 by </B><A HREF=/tutors/aboutme.mpl?userid=subudear><B>subudear(62)</B></A><img src=\"/images/stars/stars-08.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=subudear><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=466675\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let speed of water in river be u kmph<BR>\n" );
document.write( "Let speed of boat in still water (water not moving) be v kmph\r<BR>\n" );
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document.write( "then time taken by boat to row DOWN the river will be\r<BR>\n" );
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document.write( "t*(v + u) = d  ...(1)\r<BR>\n" );
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document.write( "t = time taken to row down, speed of boat will be  (u+v) as flowing water will help boat go fast, d=distance traveled down stream \r<BR>\n" );
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document.write( "Similarly time time taken by boat to row UP the river will be\r<BR>\n" );
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document.write( "4t*(v - u) = d   .....(2)\r<BR>\n" );
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document.write( "t = time taken to row UP which is 4 times the time taken to row DOWN, speed of boat will be  (v - u) as flowing water will slowdown the boat, d=distance traveled down stream \r<BR>\n" );
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document.write( "As distance is same so equating both equations\r<BR>\n" );
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document.write( "t*(v + u) = 4t*(v - u)\r<BR>\n" );
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document.write( "This gives 5*u = 3*v\r<BR>\n" );
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document.write( "Now it is given that water speed is 6 kmph which means u = 6 kmph\r<BR>\n" );
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document.write( "substituting the value we get \r<BR>\n" );
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document.write( "v = 10 kmph\r<BR>\n" );
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document.write( "Speed of boat in still water is 10 kmph </SPAN>\n" );
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