document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=772723>Question 772723</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A student drives from home to school at an average speed of 40 km/hr and returns home at an average speed of 60 km/hr. Find the average speed for the entire trip? Why is your answer not 50 km/hr? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #471170 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=471170\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A student drives from home to school at an average speed of 40 km/hr and returns home at an average speed of 60 km/hr.<BR>\n" );
document.write( " Find the average speed for the entire trip? <BR>\n" );
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document.write( "Let d = the one-way distance<BR>\n" );
document.write( "Let a = the average speed for the round trip<BR>\n" );
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document.write( "Write time equation; time = dist/speed<BR>\n" );
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document.write( "To sch time + return time = total time<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F40 ALIGN=MIDDLE  ALT=\"d%2F40\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F60 ALIGN=MIDDLE  ALT=\"d%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%282d%29%2Fa ALIGN=MIDDLE  ALT=\"%282d%29%2Fa\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "multiply equation by 120 a to clear the denominators, results:<BR>\n" );
document.write( "3ad + 2ad = 120(2d)<BR>\n" );
document.write( "5ad = 240d<BR>\n" );
document.write( "divide both sides by d<BR>\n" );
document.write( "5a = 240<BR>\n" );
document.write( "a = 240/5<BR>\n" );
document.write( "a = 48 mph is the average speed<BR>\n" );
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document.write( "Why is your answer not 50 km/hr? Because you spend more time driving 40 <BR>\n" );
document.write( "than you do a 60. </SPAN>\n" );
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