document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=544531>Question 544531</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You are to travel from point A to point B and return.On the trip from A to B,you travel at 30 miles per hour. How fast would you have to travel from B to A in order to average 60 miles per hour fro the round trip? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #355129 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=355129\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Average speed is always ( total distance ) / ( total time )<BR>\n" );
document.write( "Call the distance between A and B <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d ALIGN=MIDDLE  ALT=\"d\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r ALIGN=MIDDLE  ALT=\"r\"   DISABLED_style= \"max-width:90%; height:auto;\" > = rate on B to A trip<BR>\n" );
document.write( "Going from A to B:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+30t%5B1%5D+ ALIGN=MIDDLE  ALT=\"+d+=+30t%5B1%5D+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t%5B1%5D+=+d%2F30+ ALIGN=MIDDLE  ALT=\"+t%5B1%5D+=+d%2F30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Going from B to A:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+r%2At%5B2%5D+ ALIGN=MIDDLE  ALT=\"+d+=+r%2At%5B2%5D+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t%5B2%5D+=+d%2Fr+ ALIGN=MIDDLE  ALT=\"+t%5B2%5D+=+d%2Fr+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The average speed is<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%282d%29+%2F+%28+t%5B1%5D+%2B+t%5B2%5D+%29+ ALIGN=MIDDLE  ALT=\"+%282d%29+%2F+%28+t%5B1%5D+%2B+t%5B2%5D+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%282d%29+%2F+%28d%2F30+%2B+d%2Fr+%29+ ALIGN=MIDDLE  ALT=\"+%282d%29+%2F+%28d%2F30+%2B+d%2Fr+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Divide top and bottom by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d ALIGN=MIDDLE  ALT=\"d\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2+%2F+%28+1%2F30+%2B+1%2Fr+%29+ ALIGN=MIDDLE  ALT=\"+2+%2F+%28+1%2F30+%2B+1%2Fr+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "If average speed is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60 ALIGN=MIDDLE  ALT=\"60\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+60+=+2+%2F+%28+1%2F30+%2B+1%2Fr+%29+ ALIGN=MIDDLE  ALT=\"+60+=+2+%2F+%28+1%2F30+%2B+1%2Fr+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+60%2A%28+1%2F30+%2B+1%2Fr+%29+=+2+ ALIGN=MIDDLE  ALT=\"+60%2A%28+1%2F30+%2B+1%2Fr+%29+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2+%2B+60%2Fr+=+2+ ALIGN=MIDDLE  ALT=\"+2+%2B+60%2Fr+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+60%2Fr+=+0+ ALIGN=MIDDLE  ALT=\"+60%2Fr+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+r+ ALIGN=MIDDLE  ALT=\"+r+\"   DISABLED_style= \"max-width:90%; height:auto;\" > has to be infinite, so you can't possibly average 60 mi/hr<BR>\n" );
document.write( "check: What if average speed must be 59 mi/hr?<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+59+=+2+%2F+%28+1%2F30+%2B+1%2Fr+%29+ ALIGN=MIDDLE  ALT=\"+59+=+2+%2F+%28+1%2F30+%2B+1%2Fr+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+59%2A%281%2F30+%2B+1%2Fr+%29+=+2+ ALIGN=MIDDLE  ALT=\"+59%2A%281%2F30+%2B+1%2Fr+%29+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+59%2F30+%2B+59%2Fr+=+2+ ALIGN=MIDDLE  ALT=\"+59%2F30+%2B+59%2Fr+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+59%2Fr+=+60%2F30+-+59%2F30+ ALIGN=MIDDLE  ALT=\"+59%2Fr+=+60%2F30+-+59%2F30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+59%2Fr+=+1%2F30+ ALIGN=MIDDLE  ALT=\"+59%2Fr+=+1%2F30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30r ALIGN=MIDDLE  ALT=\"30r\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+59%2A30+=+r+ ALIGN=MIDDLE  ALT=\"+59%2A30+=+r+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=++r+=+1770+ ALIGN=MIDDLE  ALT=\"++r+=+1770+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr<BR>\n" );
document.write( "This is OK for a rocket to space, but not a vehicle.<BR>\n" );
document.write( "The average speed needs to be lower still\r<BR>\n" );
document.write( "\n" );
document.write( "  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );