document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=109423>Question 109423</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 4 people, starting on the same side, want to cross a bridge. All have to be across in 17 minutes or less. It is night. They have one flashlight, which must accompany them across.  A max of 2 people can go at once. The flashlight cannot be thrown. It must be walked back and forth.  Each person walks a different speed and pairs must walk together at a rate of the slower person's pace.  The 4 persons crossing times are as follows: P1 = 1 min.; P2 = 2 min.; P3 = 5 min., P4 = 10 min.  How do you solve this? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #79788 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=79788\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> this cannot be done in the allotted time\r<BR>\n" );
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document.write( "the fastest person (P1) must accompany each crossing so that the flashlight returns in the shortest time\r<BR>\n" );
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document.write( "10+5+2=17 ... but that does not take into account the returning of the flashlight\r<BR>\n" );
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document.write( "**ENLIGHTENMENT** ... thanks to Dushenko\r<BR>\n" );
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document.write( "the two slowest must cross together to minimize their time impact<BR>\n" );
document.write( "... this means the two fastest must cross together leaving a \"faster\" person on each side to return the light\r<BR>\n" );
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document.write( "the two fastest people cross first, one stays and the other returns with the light<BR>\n" );
document.write( "... next, the two slowest people cross and the faster returns with the light<BR>\n" );
document.write( "... lastly, the two fastest people cross </SPAN>\n" );
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