document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=143301>Question 143301</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Chris and Michelle arrive in North Carolina by plane at 7:00 a.m. After renting their car, they head towards their hotel. On the way they must pass over an extremely sloped 2 mile hill.  \r<BR>\n" );
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document.write( "Chris tells Michelle that he is going to average 30 mph for the 2 miles (to the top and back down).  Michelle says, “Okay, go for it.” \r<BR>\n" );
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document.write( "Chris begins by driving slowly up the hill and reaches the top (1 mile mark) when Michelle tells him, “Chris, you better pick up the pace, it has taken 4 minutes to get to the top and we still have 1 mile to go (down).” Upset Chris says, “Forget it Michelle, I can’t do this.”  Michelle says, “Sure you can.”  Chris says, “No I can’t.”\r<BR>\n" );
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document.write( "If speed and safety were not an issue, how fast must Chris travel to get to the bottom of the mountain?  Does Chris know something that Michelle does not?   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #104333 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=104333\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let's deal in minutes on this problem:\r<BR>\n" );
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document.write( "30 mph=(30*1/60 )mi/min=(1/2 )mi/min<BR>\n" );
document.write( "Distance(d) equals Rate(r) times Time(t)or d=rt;  r=d/t and t=d/r<BR>\n" );
document.write( "Also:<BR>\n" );
document.write( "Average Rate=(Total Distance)/(Total Time)\r<BR>\n" );
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document.write( "Let t=time required to travel downhill<BR>\n" );
document.write( "Total time, then, would be (4+t)<BR>\n" );
document.write( "So, our equation to solve is:<BR>\n" );
document.write( "1/2=2/(4+t)  multiply each side by 2(4+t)<BR>\n" );
document.write( "(4+t)=4 subtract 4 from each side<BR>\n" );
document.write( "t=0  THIS TELLS US THAT HE MUST TRAVEL THE SECOND MILE IN 0 TIME IN ORDER TO HAVE AN OVERALL AVERAGE OF 30 MPH\r<BR>\n" );
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document.write( "IF HE WANTS TO AVERAGE 30 MPH OR (1/2)MI/MIN OVER THE TWO MILES, THEN HIS TOTAL TIME HAS TO BE 4 MIN (2/(1/2)) BUT HE ALREADY USED UP HIS 4 MIN IN THE FIRST MILE!!!!! \r<BR>\n" );
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document.write( "HOPE THIS HELPS---PTAYLOR </SPAN>\n" );
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