document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=249429>Question 249429</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A man drives from home to work at a speed of 50mi/h. The return trip from work to home is traveled at the more leisurely pace of 30 mi/h. What is the man's average speed for the round trip?\r<BR>\n" );
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document.write( "(I know the answer is not 40mi/h though) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #181672 by </B><A HREF=/tutors/aboutme.mpl?userid=oberobic><B>oberobic(2304)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=oberobic><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=181672\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We know the basic formula for distance problems is:  d = rt, where d=distance, r=rate, t=time.<BR>\n" );
document.write( "We know the man drives to work at 50 mph.<BR>\n" );
document.write( "We know he drives home at 30 mph.<BR>\n" );
document.write( "We know the distance is the same both ways.<BR>\n" );
document.write( "What we do not know are the times involved.<BR>\n" );
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document.write( "Let's assume he drives 30 miles to and from work.<BR>\n" );
document.write( "At 50 mph it takes him 30/50 or .6 of an hour to drive to work.  .6*60 = 36 minutes<BR>\n" );
document.write( "At 30 mph it takes him 30/30 or 1 hr to drive home = 60 minutes<BR>\n" );
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document.write( "So the total elapsed time is 96 minutes to drive 60 miles.<BR>\n" );
document.write( "96 minutes = 1.6 hr<BR>\n" );
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document.write( "Going back to d=rt<BR>\n" );
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document.write( "60 miles = r mph * 1.6 hr = 1.6r<BR>\n" );
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document.write( "Dividing both sides by 1.6<BR>\n" );
document.write( "37.5 = r<BR>\n" );
document.write( "r = 37.5<BR>\n" );
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document.write( "Checking our work...<BR>\n" );
document.write( "How far will the car go in 1.6 hr at 37.5 mph?<BR>\n" );
document.write( "60 miles<BR>\n" );
document.write( "OK. </SPAN>\n" );
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