document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=63914>Question 63914</A>: <I><SPAN STYLE=\"word-break: break-all;\"> if it takes the faucet 21 minutes to fill the tub, and it takes the drain 28 minutes to empty the tub, how long will it take to fill the tub, if grandma forgets to close the drain while filling it? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #44559 by </B><A HREF=/tutors/aboutme.mpl?userid=rajagopalan><B>rajagopalan(174)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rajagopalan><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=rajagopalan><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=44559\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You solve it like this:\r<BR>\n" );
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document.write( "Filling  time   21 min<BR>\n" );
document.write( "Filling  Rate   1/21 of the tub per minute....A<BR>\n" );
document.write( "Draining Rate   1/28 of the tub per minute....B<BR>\n" );
document.write( "So, Net Filling rate (NFR) = A-B = (1/21) - (1/28)<BR>\n" );
document.write( "Taking LCM of 84, we get NFR = (4/84)-(3/84)=1/84\r<BR>\n" );
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document.write( "For filling 1/84 of the tub it takes 1 minute<BR>\n" );
document.write( "for filling full tub ie 84/84 it will take 84 minutes.\r<BR>\n" );
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document.write( "Good day..<BR>\n" );
document.write( "Cross Check : <BR>\n" );
document.write( "In 84 minutes the fill  pipe will pour  4 times the tub volume<BR>\n" );
document.write( "In 84 minutes the Drain pipe will drain 3 times the tub volume\r<BR>\n" );
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document.write( "We have one volume of water in tub.<BR>\n" );
document.write( "Ok!  </SPAN>\n" );
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