document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=491674>Question 491674</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose you are moving, and have 9 boxes.  For this problem, order is not important.\r<BR>\n" );
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document.write( "i) find the number of ways of selecting 4 boxes out of 9.\r<BR>\n" );
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document.write( "ii) Suppose one box has your wallet.  Find the number of ways of selecting 4 boxes, so that the box with your wallet is one of the four.  (Hint: how many ways of getting 3 more boxes out of the remaining 8 are there?)\r<BR>\n" );
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document.write( "iii) If you select 4 boxes at random, find the probability that your wallet will be in one of these four.  Use the results from parts i and ii to answer this problem.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #334738 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=334738\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Suppose you are moving, and have 9 boxes. For this problem, order is not important. <BR>\n" );
document.write( "i) find the number of ways of selecting 4 boxes out of 9.<BR>\n" );
document.write( "Ans: 9C4 = (9*8*7*6)/(1*2*3*4) = 126<BR>\n" );
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document.write( "ii) Suppose one box has your wallet. Find the number of ways of selecting 4 boxes, so that the box with your wallet is one of the four. (Hint: how many ways of getting 3 more boxes out of the remaining 8 are there?)<BR>\n" );
document.write( "Ans = 8C3 = 56<BR>\n" );
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document.write( "iii) If you select 4 boxes at random, find the probability that your wallet will be in one of these four. Use the results from parts i and ii to answer this problem. <BR>\n" );
document.write( "Ans = 1 - [56/126] = 1 - 0.4444 = 0.5556<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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