document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=619487>Question 619487</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two trains leave Chicago at the same time and in opposite directions. One is going 120MPH and one is going 130MPH. How long before they are 750 miles apart?<BR>\n" );
document.write( "Answer: 6\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "I am not sure my equation is correct.\r<BR>\n" );
document.write( "\n" );
document.write( "750/120=6<BR>\n" );
document.write( "750/130= 5.7\r<BR>\n" );
document.write( "\n" );
document.write( "I rounded up and came to conclusion that 6hr would be the average time. Is this correct? If not whats the equation I need to use. Thank you.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #389674 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=389674\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Train 1: \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "d = rt\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "d = 120t\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Train 2:\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "d = rt\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "d = 130t\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "--------------------------\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "So train 1 has traveled 120t miles in t hours and train 2 has traveled 130t miles in t hours.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Since they are going in opposite directions (along let's assume a straight track), they will be 120t+130t = 250t miles apart after t hours.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "We want this distance to be 750, so \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "250t = 750\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "t = 750/250\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "t = 3\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "So in <font color=\"red\">3 hours</font>, the two trains will be 750 miles apart. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );