document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=230679>Question 230679</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 an empty tank can be filled in 45 minutes with the inlet pipe opened.  If both pipes are accidently openedwhen the tank is full, then how long will it take to empty the tank? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #170867 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=170867\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It doesn't really matter how big the tank is,<BR>\n" );
document.write( "because the 2 pipes will just get bigger and<BR>\n" );
document.write( "bigger to fill or empty a bigger tank.<BR>\n" );
document.write( "I'll say the tank holds 90 gallons when it's full<BR>\n" );
document.write( "The rate of filling an empty tank is:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=90%2F45 ALIGN=MIDDLE  ALT=\"90%2F45\"   DISABLED_style= \"max-width:90%; height:auto;\" > gallons/min<BR>\n" );
document.write( "The rate of emptying a full tank is:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-%2890%2F30%29 ALIGN=MIDDLE  ALT=\"-%2890%2F30%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > gallons/min<BR>\n" );
document.write( "(the minus sign is the only way I can <BR>\n" );
document.write( "tell if I'm emptying of filling)<BR>\n" );
document.write( "----------------------------------------<BR>\n" );
document.write( "If both outlet and inlet are opened, I simply<BR>\n" );
document.write( "add the 2 rates, still using the minus for emptying<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=90%2F45+-+90%2F30+=+r ALIGN=MIDDLE  ALT=\"90%2F45+-+90%2F30+=+r\"   DISABLED_style= \"max-width:90%; height:auto;\" > gallons/min<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2+-+3+=+r ALIGN=MIDDLE  ALT=\"2+-+3+=+r\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+-1 ALIGN=MIDDLE  ALT=\"r+=+-1\"   DISABLED_style= \"max-width:90%; height:auto;\" > gallons/min<BR>\n" );
document.write( "The tank is emptying at this rate with both pipes open<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=90%2F-1+=+-90 ALIGN=MIDDLE  ALT=\"90%2F-1+=+-90\"   DISABLED_style= \"max-width:90%; height:auto;\" > min<BR>\n" );
document.write( "With both pipes open, the 90 gallon tank <BR>\n" );
document.write( "empties in 90 min\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
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