document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=29961>Question 29961</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Elvin drove halfway from ashton to dover at 40 mi/h abd the rest of the way at 60 mi/h. What was his average speed for the whole trip? (Hint: let the distance for the whole trip be, say, 100 mi.) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #16725 by </B><A HREF=/tutors/aboutme.mpl?userid=Earlsdon><B>Earlsdon(6294)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Earlsdon><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=16725\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> First, let's find the time it took Elvin to drive each leg of the trip.\r<BR>\n" );
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document.write( "First leg:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t1+=+d1%2Fr1 ALIGN=MIDDLE  ALT=\"t1+=+d1%2Fr1\"   DISABLED_style= \"max-width:90%; height:auto;\" > d1 = 40 miles and r1 = 40 mph.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t1+=+40%2F40 ALIGN=MIDDLE  ALT=\"t1+=+40%2F40\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t1+=+1 ALIGN=MIDDLE  ALT=\"t1+=+1\"   DISABLED_style= \"max-width:90%; height:auto;\" >hour.\r<BR>\n" );
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document.write( "Second leg:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t2+=+d2%2Fr2 ALIGN=MIDDLE  ALT=\"t2+=+d2%2Fr2\"   DISABLED_style= \"max-width:90%; height:auto;\" > d2 = 40 miles and r2 = 60 mph.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t2+=+40%2F60 ALIGN=MIDDLE  ALT=\"t2+=+40%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t2+=+2%2F3 ALIGN=MIDDLE  ALT=\"t2+=+2%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours.\r<BR>\n" );
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document.write( "Now we need to find the \"weighted\" average speed for the entire trip.  Let's call that M.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M+=+%28r1%2At1+%2B+r2%2At2%29%2F%28t1%2Bt2%29 ALIGN=MIDDLE  ALT=\"M+=+%28r1%2At1+%2B+r2%2At2%29%2F%28t1%2Bt2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M+=+%2840%2A1+%2B+60%282%2F3%29%29%2F%285%2F3%29 ALIGN=MIDDLE  ALT=\"M+=+%2840%2A1+%2B+60%282%2F3%29%29%2F%285%2F3%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M+=+%2840%2B40%29%2F%285%2F3%29 ALIGN=MIDDLE  ALT=\"M+=+%2840%2B40%29%2F%285%2F3%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M+=+80%283%2F5%29 ALIGN=MIDDLE  ALT=\"M+=+80%283%2F5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M+=+48 ALIGN=MIDDLE  ALT=\"M+=+48\"   DISABLED_style= \"max-width:90%; height:auto;\" >mph. </SPAN>\n" );
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