document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=772695>Question 772695</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A large water tank has two inlet pipes of different sizes, and one outlet pipe. With the outlet pipe closed, it takes 3 hours to fill the empty tank using the large inlet pipe only. It takes 4 hours to fill the empty tank using the small inlet pipe only. When the tank is full, and the inlet pipes are closed, it takes the outlet pipe 8 hours to empty the tank. Assuming the tank is empty and all three pipes are opened, how long will it take to fill the tank, to the nearest minute? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #471064 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=471064\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Add the rates of filling and subtract<BR>\n" );
document.write( "the rate of emptying<BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "Large pipe's rate:<BR>\n" );
document.write( "( 1 tank ) / ( 3 hrs )<BR>\n" );
document.write( "Small pipe's rate:<BR>\n" );
document.write( "( 1 tank ) ( 4 hrs )<BR>\n" );
document.write( "Outlet pipe's rate:<BR>\n" );
document.write( "( 1 tank ) / ( 8 hrs )<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = time in hrs to fill<BR>\n" );
document.write( "tank with all 3 open<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1%2F3+%2B+1%2F4+-+1%2F8+=+1%2Ft+ ALIGN=MIDDLE  ALT=\"+1%2F3+%2B+1%2F4+-+1%2F8+=+1%2Ft+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+24t+ ALIGN=MIDDLE  ALT=\"+24t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+8t+%2B+6t+-+3t+=+24+ ALIGN=MIDDLE  ALT=\"+8t+%2B+6t+-+3t+=+24+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+11t+=+24+ ALIGN=MIDDLE  ALT=\"+11t+=+24+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+24%2F11+ ALIGN=MIDDLE  ALT=\"+t+=+24%2F11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2.1818+ ALIGN=MIDDLE  ALT=\"+2.1818+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+.1818%2A60+=+10.91+ ALIGN=MIDDLE  ALT=\"+.1818%2A60+=+10.91+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "It takes 2 hrs and 11 minutes to fill tank<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );