document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=253212>Question 253212</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A water tank has an inlet pipe and a drain pipe. A full tank can be emptied in 30 minutes if the drain is opened and empty tank can be filled in 45 minutess with the inlet pipe opened.  If both pipes are accidently opened when the tank is full, then how long would it take to empty the tank?\r<BR>\n" );
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document.write( "I believe this is a trick question and can possible be unknown. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #185451 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=185451\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We had a similar  problem in the last week or so.<BR>\n" );
document.write( "This version starts with a full tank and drains faster than it fills.<BR>\n" );
document.write( "t/30-t/45=1<BR>\n" );
document.write( "Let's think about this.<BR>\n" );
document.write( "If the fill pipe were closed it would take 30 minutes<BR>\n" );
document.write( "So after 30 minutes the original water is gone.<BR>\n" );
document.write( "In the meantime, it has filled up for 30 minutes. Let's deal with a complete refill.<BR>\n" );
document.write( "It can fill in 45 minutes but has only has 30 minutes so it refilled 2/3<BR>\n" );
document.write( "So after 45 minutes it will have filled again but the first fill is gone and the drain has had 15 minutes to empty it.<BR>\n" );
document.write( "So it emptied half of it.  To empty all of it it needs another 45 minutes.<BR>\n" );
document.write( "So it would take 90 minutes to empty the full tank with the fill pipe opened.<BR>\n" );
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