document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=375958>Question 375958</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You own 17 CDs. You want to randomly arrange 9 of them in a CD rack. What is the probability that the rack ends up in alphabetical order?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #710812 by </B><A HREF=/tutors/aboutme.mpl?userid=Alyrian><B>Alyrian(2)</B></A><img src=\"/images/stars/iconNewId_16x16.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alyrian><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=710812\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You can't just assume there's one solution in all the permutations. Nor can you assume that just choosing is a solution. \r<BR>\n" );
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document.write( "The real solution here is finding all possible permutations of size 9 you can get from 17, or 17P9. Then you need to find all the possible ways a unique set of 9 things can be pulled from a total of 17, or 17C9 (because each set of 9 from 17 will have a correct alphabetical order).\r<BR>\n" );
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document.write( "Thus, the probability that your rack will end up in alphabetical order will be (17C9)/(17P9). This is 24310/8821612800.\r<BR>\n" );
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document.write( "Hope this helps! </SPAN>\n" );
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