document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=987684>Question 987684</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A car traveled from city X to city Y at a uniform speed of 120 miles/ hr. The car then travels from city Y to city Z at a uniform speed of eof 100miles/ hr. If the distance the car travelled  city X and Y is twice the distance the car travelled between city Y and Z , what is the average speed in miles per hour the car travelled between city X and Z\r<BR>\n" );
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document.write( "Many thanks for your help <BR>\n" );
document.write( "Manoj </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #608524 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=608524\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A car traveled from city X to city Y at a uniform speed of 120 miles/ hr.<BR>\n" );
document.write( " The car then travels from city Y to city Z at a uniform speed of of 100miles/ hr.<BR>\n" );
document.write( " If the distance the car travelled city X and Y is twice the distance the car travelled between city Y and Z , what is the average speed in miles per hour the car travelled between city X and Z <BR>\n" );
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document.write( "let a = the average speed of the whole trip<BR>\n" );
document.write( "let d = the distance from y to z<BR>\n" );
document.write( " we know the dist from x to y, is twice the dist from y to z, therefore<BR>\n" );
document.write( "2d = the distance from x to y<BR>\n" );
document.write( "and<BR>\n" );
document.write( "3d = the total distance from x to z<BR>\n" );
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document.write( "Write a time equation, time = dist/speed<BR>\n" );
document.write( "xy time + yz time = total time<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%282d%29%2F120 ALIGN=MIDDLE  ALT=\"%282d%29%2F120\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F100 ALIGN=MIDDLE  ALT=\"d%2F100\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%283d%29%2Fa ALIGN=MIDDLE  ALT=\"%283d%29%2Fa\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "multiply by 600a<BR>\n" );
document.write( "600a*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%282d%29%2F120 ALIGN=MIDDLE  ALT=\"%282d%29%2F120\"   DISABLED_style= \"max-width:90%; height:auto;\" > + 600a*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F100 ALIGN=MIDDLE  ALT=\"d%2F100\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 600a*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%283d%29%2Fa ALIGN=MIDDLE  ALT=\"%283d%29%2Fa\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Cancel the denominators<BR>\n" );
document.write( "5a(2d) + 6ad = 600(3d)<BR>\n" );
document.write( "10ad + 6ad = 1800d<BR>\n" );
document.write( "16ad = 1800d<BR>\n" );
document.write( "simplify divide both sides by d<BR>\n" );
document.write( "16a = 1800<BR>\n" );
document.write( "a = 1800/16<BR>\n" );
document.write( "a = 112.5 mph av speed for x to z<BR>\n" );
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document.write( "We can confirm this by choosing a value for d, say 100 mi, and finding the times<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=200%2F120 ALIGN=MIDDLE  ALT=\"200%2F120\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=100%2F100 ALIGN=MIDDLE  ALT=\"100%2F100\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2F112.5 ALIGN=MIDDLE  ALT=\"300%2F112.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "1.67 + 1 = 2.67<BR>\n" );
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document.write( "Equation will be correct for any value of d\r<BR>\n" );
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document.write( " </SPAN>\n" );
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