document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=768558>Question 768558</A>: <I><SPAN STYLE=\"word-break: break-all;\"> At 1 pm, Poseidon opened pipe A to fill an empty tank with water. Two hours later, Zeus opened pipe B which also fills the tank, but accidentally opened pipe X which drains the tank. At 4 pm, evil Hades closed both pipes A and B. With pipe X left open, the tank was completely drained at 6:45 pm. If pipe X alone can empty the full tank in 5 hours, while pipe B alone can fill up the empty tank in 4 hours, how long will it take pipe A alone to fill up the empty tank? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #468460 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=468460\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> At 1 pm, Poseidon opened pipe A to fill an empty tank with water.<BR>\n" );
document.write( " Two hours later, Zeus opened pipe B which also fills the tank, but accidentally opened pipe X which drains the tank.<BR>\n" );
document.write( " At 4 pm, evil Hades closed both pipes A and B. With pipe X left open, the tank was completely drained at 6:45 pm.<BR>\n" );
document.write( " If pipe X alone can empty the full tank in 5 hours, while pipe B alone can fill up the empty tank in 4 hours, how long will it take pipe A alone to fill up the empty tank?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "From the information given we know:<BR>\n" );
document.write( "Pipe A ran from 1 pm to 4 pm; 3 hrs<BR>\n" );
document.write( "Pipe B ran from 3 pm to 4 pm; 1 hr<BR>\n" );
document.write( "Pipe x ran from 3 pm to 6:45; 3.75 hrs<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Let A = time for pipe A to fill the tank by itself<BR>\n" );
document.write( "Let a full tank = 1<BR>\n" );
document.write( "then<BR>\n" );
document.write( "An empty tank = 0: <BR>\n" );
document.write( ":<BR>\n" );
document.write( "Pipe A + pipe B - pipe x = empty tank<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2FA ALIGN=MIDDLE  ALT=\"3%2FA\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3.75%2F5 ALIGN=MIDDLE  ALT=\"3.75%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <BR>\n" );
document.write( "multiply by 20A, clear the denominators, resulting in<BR>\n" );
document.write( "20(3) + 5A - 4A(3.75) = 0<BR>\n" );
document.write( "60 + 5A - 15A = 0<BR>\n" );
document.write( "60 - 10A = 0<BR>\n" );
document.write( "60 = 10A<BR>\n" );
document.write( "A = 160/10<BR>\n" );
document.write( "A = 6 hrs to fill the tank alone<BR>\n" );
document.write( " </SPAN>\n" );
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