document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=791031>Question 791031</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a car travels from station a to b at 30kmph during its return trip to A,it travels at 30kmph for half of the distance and at 70kmph for next half of the distance.find average speed of the car?\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #479403 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=479403\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  a car travels from station a to b at 30kmph during its return trip to A,it travels at 30kmph for half of the distance and at 70kmph for next half of the distance.find average speed of the car?<BR>\n" );
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document.write( "Let d = the distance from a to b<BR>\n" );
document.write( "then<BR>\n" );
document.write( ".5d = half the distance from a to b<BR>\n" );
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document.write( "Let a = average speed for the round trip<BR>\n" );
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document.write( "Write a time equation: time = dist/speed.<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F30 ALIGN=MIDDLE  ALT=\"d%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28.5d%29%2F30 ALIGN=MIDDLE  ALT=\"%28.5d%29%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28.5d%29%2F70 ALIGN=MIDDLE  ALT=\"%28.5d%29%2F70\"   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( "Add like terms<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281.5d%29%2F30 ALIGN=MIDDLE  ALT=\"%281.5d%29%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28.5d%29%2F70 ALIGN=MIDDLE  ALT=\"%28.5d%29%2F70\"   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 by 210a, resulting in<BR>\n" );
document.write( "7a(1.5d) + 3a(.5d) = 210(2d)<BR>\n" );
document.write( "10.5ad + 1.5ad = 420d<BR>\n" );
document.write( "12ad = 420d<BR>\n" );
document.write( "divide both sides by d<BR>\n" );
document.write( "12a = 420<BR>\n" );
document.write( "a = 420/12<BR>\n" );
document.write( "a = 35 mph is the average speed<BR>\n" );
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document.write( "You can check this yourself, use d=60 to find the actual time at each speed </SPAN>\n" );
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