document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=963673>Question 963673</A>: <I><SPAN STYLE=\"word-break: break-all;\"> most tunnels are drilled using tunnel-boring machines that begin at both ends of the tunnel. suppose a new tunnel is being built and one tunnel-boring machine alone can finish the tunnel in 4 years. a different type of machine can tunnel to the other side in 3 years if both machines start at a opposite ends and work at the same time, when will the tunnel be finished? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #588756 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=588756\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> most tunnels are drilled using tunnel-boring machines that begin at both ends of the tunnel. suppose a new tunnel is being built and one tunnel-boring machine alone can finish the tunnel in 4 years.<BR>\n" );
document.write( " a different type of machine can tunnel to the other side in 3 years if both machines start at a opposite ends and work at the same time, when will the tunnel be finished?<BR>\n" );
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document.write( "let t = time required when both drills are used<BR>\n" );
document.write( "let the completed job = 1<BR>\n" );
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document.write( "Each machine will do a fraction of the job, the two fractions add up to 1<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%2F4 ALIGN=MIDDLE  ALT=\"t%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%2F3 ALIGN=MIDDLE  ALT=\"t%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "multiply equation by 12, cancel the denominators, you have:<BR>\n" );
document.write( "3t + 4t = 12<BR>\n" );
document.write( "7t = 12<BR>\n" );
document.write( "t = 12/7<BR>\n" );
document.write( "t = 1.714 years or 1 + .714(365) = 1 yr 261 days to finish the tunnel </SPAN>\n" );
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