document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=663631>Question 663631</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two trains set off at the same time from each end of a single straight railway line, which is 100km long. The first train travels at a constant speed of 55km/hour. the second train travels at a constant speed of 70km/hr. A very fast fly, Fred, travels at 100km/hr. Fred starts off in front of the first train and flys continuously back and forth between the two trains. How far does Fred fly before he is squashed between the two trains?\r<BR>\n" );
document.write( "\n" );
document.write( "  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #412861 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16949)</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=412861\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Train I speed = 55 km/h<BR>\n" );
document.write( "Train II speed = 70 km/h\r<BR>\n" );
document.write( "\n" );
document.write( "They are moving towards each other<BR>\n" );
document.write( "so add up the speeds.<BR>\n" );
document.write( "combined speed = 125 km/h\r<BR>\n" );
document.write( "\n" );
document.write( "Distance = 100 km\r<BR>\n" );
document.write( "\n" );
document.write( "Time taken by the trains to meet will be t= d/s\r<BR>\n" );
document.write( "\n" );
document.write( "100/125 = 4/5 of an hour\r<BR>\n" );
document.write( "\n" );
document.write( "During this time the fly is flying continuously.<BR>\n" );
document.write( "speed = 100 km/h\r<BR>\n" );
document.write( "\n" );
document.write( "distance traveled by Fred = speed * time<BR>\n" );
document.write( "100 * 4/5 = 80 km\r<BR>\n" );
document.write( "\n" );
document.write( "m.ananth@hotmail.ca </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );