document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=285929>Question 285929</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Filling a tank. 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 an empty tank can be filled in 45 minutes with the inlet pipe opened. If both pipes are accidentally opened when the tank is full, then how long will it take to empty the tank?<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 #207374 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=207374\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x/45-x/30=1<BR>\n" );
document.write( "We start with the tank full and are filling it and draining it.<BR>\n" );
document.write( "x=-90<BR>\n" );
document.write( "means it takes 90 minutes to drain it<BR>\n" );
document.write( "in 90 minutes<BR>\n" );
document.write( "We start with a full tank. It is filled 2 more times and drained 3 times  </SPAN>\n" );
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