document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=761369>Question 761369</A>: <I><SPAN STYLE=\"word-break: break-all;\"> One pipe can fill a tank in 45 minutes and another pipe can fill it in 30 minutes. if these two pipes are open and a third pipe is draining water from the tank, it takes 27 minutes to fill the tank. How long will it take the third pipe alone to empty a full tank </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #463191 by </B><A HREF=/tutors/aboutme.mpl?userid=ramkikk66><B>ramkikk66(644)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ramkikk66><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=463191\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let the tank's capacity be C.\r<BR>\n" );
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document.write( "P1 takes 45 min to fill the tank. So in 1 minute, P1 will fill 1/45 of the tank.\r<BR>\n" );
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document.write( "Similarly, in 1 minute, P2 will fill 1/30 of the tank.\r<BR>\n" );
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document.write( "Together, in 1 minute, they will fill out <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F45+%2B+1%2F30+=+5%2F90+=+1%2F18 ALIGN=MIDDLE  ALT=\"1%2F45+%2B+1%2F30+=+5%2F90+=+1%2F18\"   DISABLED_style= \"max-width:90%; height:auto;\" > of the tank.\r<BR>\n" );
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document.write( "So, together, they will take 18 minutes to fill the tank - if there was no drainage.\r<BR>\n" );
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document.write( "But because of the drainage, they take 27 min. So the effective rate of filling is not 1/18 but 1/27 per min.\r<BR>\n" );
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document.write( "Effective rate = Rate of P1 + Rate of P2 - Rate of P3 (drainage pipe)\r<BR>\n" );
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document.write( "Substituting,\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F27+=+1%2F45+%2B+1%2F30+-+P3 ALIGN=MIDDLE  ALT=\"1%2F27+=+1%2F45+%2B+1%2F30+-+P3\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "P3 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F18+-+1%2F27+=+1%2F54 ALIGN=MIDDLE  ALT=\"1%2F18+-+1%2F27+=+1%2F54\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "i.e. P3 empties 1/54 of the tank every minute.\r<BR>\n" );
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document.write( "So it would take P3 54 minutes to empty a full tank.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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