document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=417738>Question 417738</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two trains, each two miles long, enter two one mile long tunnels that are two miles apart from one another on the same track. The trains enter the tunnels at exactly the same time. The first train is going 5 miles/hour, and the second train is going 10 miles/hour. What is the sum of the lengths of the two trains that will protrude from the tunnels at the exact moment that they collide, assuming that neither train changes its speed prior to collision? The trains are on the same track headed in opposite directions </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #292434 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=292434\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Two trains, each two miles long, enter two one mile long tunnels that are two miles apart from one another on the same track. The trains enter the tunnels at exactly the same time. The first train is going 5 miles/hour, and the second train is going 10 miles/hour. What is the sum of the lengths of the two trains that will protrude from the tunnels at the exact moment that they collide, assuming that neither train changes its speed prior to collision? The trains are on the same track headed in opposite directions\r<BR>\n" );
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document.write( "length of each train 2 miles<BR>\n" );
document.write( "length of each tunnel = 1<BR>\n" );
document.write( "two tunnels = 2miles.<BR>\n" );
document.write( "distance betweeen two tunnels = 2miles<BR>\n" );
document.write( "Total distance = 4 miles.<BR>\n" );
document.write( "...<BR>\n" );
document.write( "first train 5 mph<BR>\n" );
document.write( "second 10 mph.<BR>\n" );
document.write( "they are moving towards each other. so effective speed = 15 mph.<BR>\n" );
document.write( "time taken to collide = 4/15  hours.<BR>\n" );
document.write( "..<BR>\n" );
document.write( "speed of first train = 5mph<BR>\n" );
document.write( "distance travelled by first train = 5*4/15 = 4/3 miles.<BR>\n" );
document.write( "length of train = 2 miles.<BR>\n" );
document.write( "so length out of the tunnel = 2-4/3= 2/3 miles.<BR>\n" );
document.write( "..<BR>\n" );
document.write( "speed of second train = 10 mph.<BR>\n" );
document.write( "distance travelled by second train = 10*4/15 = 8/3 miles<BR>\n" );
document.write( "so length out of the tunnel = 2-8/3===> -2/3 <BR>\n" );
document.write( "it means that the second train is 2/3 mile inside the tunnel\r<BR>\n" );
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document.write( "sum of the lengths outside the tunnel = 2/3 miles </SPAN>\n" );
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