document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=237092>Question 237092</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorist completes a 450 mile journey in 8 hours. Before noon on this journey, he averages 60 mph, and after noon averages 50 mph. What time did he depart and what time did he arrive?<BR>\n" );
document.write( "i figured his avg time for the whole trip was 56.25 mph, so...  im using d=rt formula, d=450; i know i don't add the 2 rates, 60 and 50 and solve for t. i tried and got 4.09, wrong. how do i go about solving ? help please-thanks </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #174381 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=174381\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A motorist completes a 450 mile journey in 8 hours. Before noon on this journey, he averages 60 mph, and after noon averages 50 mph. What time did he depart and what time did he arrive?<BR>\n" );
document.write( "-----------------------------------------------<BR>\n" );
document.write( "Before noon DATA:<BR>\n" );
document.write( "rate = 60 mph ; distance = x miles ; time = d/r = x/60 hrs<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "After noon DATA:<BR>\n" );
document.write( "rate = 50 mph ; distance = 450-x miles ; time = d/r = (450-x)/50 hrs<BR>\n" );
document.write( "-----------------------<BR>\n" );
document.write( "Equation<BR>\n" );
document.write( "time + time = 8 hrs<BR>\n" );
document.write( "x/60 + (450-x)/50 = 8<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Multiply thru by 300 to get:<BR>\n" );
document.write( "5x + 6(450-x) = 2400<BR>\n" );
document.write( "5x + 6*450 - 6x = 2400<BR>\n" );
document.write( "-x = -300<BR>\n" );
document.write( "x = 300 miles (distance traveled before noon)<BR>\n" );
document.write( "450-x = 150 miles (distance traveled after noon) <BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Time before noon = x/60 = 300/60 = 5 hr.; He left at 7:00 AM<BR>\n" );
document.write( "Time after noon = 150/50 = 3 hr. He arrived at 3:00 PM<BR>\n" );
document.write( "================================================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );