document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=861765>Question 861765</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A Motorist travels 90 kms. with the speed of 60 km/hr and the next 40 kms distance with the speed of 40 km/hr. what is his average speed during the journey?\r<BR>\n" );
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document.write( "1) 50kms/hr<BR>\n" );
document.write( "2) 100kms/hr<BR>\n" );
document.write( "3) 45kms/hr<BR>\n" );
document.write( "4) 48kms/hr\r<BR>\n" );
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document.write( "My Solution:<BR>\n" );
document.write( "Finding times for two cases by the formula Total Time = Total Distance / Avg. Speed\r<BR>\n" );
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document.write( "Case 1:<BR>\n" );
document.write( "Time = 90kms / 60kms/hr = 1.5hrs\r<BR>\n" );
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document.write( "Case 2:<BR>\n" );
document.write( "Time = 40kms / 40kms/hr = 1hr\r<BR>\n" );
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document.write( "Adding two times = 2.5hrs<BR>\n" );
document.write( "Adding two distances = 130kms\r<BR>\n" );
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document.write( "We find avg speed = 130 / 2.5 = 52kms/hr\r<BR>\n" );
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document.write( "But the answer is wrong this way.\r<BR>\n" );
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document.write( "One more simple thing i did is find the average of = (40 kms/hr + 60 kms/hr)/2 = 50km/hr which is also wrong.\r<BR>\n" );
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document.write( "The Answer is 48km/hr. Please explain how. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #519234 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=519234\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The answer is 52.<BR>\n" );
document.write( "r*t=d<BR>\n" );
document.write( "r=d/t\r<BR>\n" );
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document.write( "To get average speed you take total distance /total time=average speed<BR>\n" );
document.write( "90/60=1.5 hours<BR>\n" );
document.write( "40/40=1<BR>\n" );
document.write( "1+1.5=2.5 hours\r<BR>\n" );
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document.write( "90+40=130<BR>\n" );
document.write( "130/2.5=52<BR>\n" );
document.write( "the book is wrong.<BR>\n" );
document.write( "They must have changed the problem and forgot to change the solution and choices.<BR>\n" );
document.write( "Unfortunately that happens all too often.\r<BR>\n" );
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document.write( "Double check the numbers and make sure you copied them correctly.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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