document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1170496>Question 1170496</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi<BR>\n" );
document.write( "Guan heng left P and drove at 72kmph for 45 min. Then he increased his speed to 84kmph and drove for a further 40mins prior to reaching his home. His sister left P 20min earlier than him but she reached her home 25 min later.\r<BR>\n" );
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document.write( "What was his sisters average speed \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 #795364 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=795364\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> rate * time = distance\r<BR>\n" );
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document.write( "72 kmph * 45/60 hours = 54 kilometers.<BR>\n" );
document.write( "84 kmph * 20/60 hours = 56 kilometers.\r<BR>\n" );
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document.write( "total distance is 110 kilometers.<BR>\n" );
document.write( "total time is (45 + 40) / 60 = 85 / 60  = 1.4166666667 hours.<BR>\n" );
document.write( "average speed is 110 kilometers / 1.4166666667 = 77.64705882 kmph.\r<BR>\n" );
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document.write( "she left 20 minutes earlier and arrived 25 minutes later.<BR>\n" );
document.write( "her time for the trip was (20 + 45 + 40 + 25) = 130 minutes / 60 = 2.166666667 hours.\r<BR>\n" );
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document.write( "her average speed was 110 / 2.166666667 = 50.76923077 kmph.\r<BR>\n" );
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document.write( "you could do this with fractions and should get the same answer.\r<BR>\n" );
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document.write( "doing it with fractions, you get:\r<BR>\n" );
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document.write( "72 kmph for 45/60 hours = a distance of 54 kilometers.<BR>\n" );
document.write( "84 kmph for 40/60 hours = a distance of 56 kilometers.\r<BR>\n" );
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document.write( "total distance is 110 kilometers.<BR>\n" );
document.write( "total time is 85/60 hours.\r<BR>\n" );
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document.write( "she started 20 minutes earlier and arrived<BR>\n" );
document.write( " 25 minutes later.<BR>\n" );
document.write( "it took her a total time of 85 + 45 = 130/60 hours.\r<BR>\n" );
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document.write( "her average speed was 110 / (130/60) = 110 * 60 / 130 = 6600/130 kmph.\r<BR>\n" );
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document.write( "6600/130 = 50.76923077 kmph.<BR>\n" );
document.write( "it's the same answer done with fractions for the intermediate calculations.\r<BR>\n" );
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