document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=563087>Question 563087</A>: <I><SPAN STYLE=\"word-break: break-all;\"> if a box contains 4 red balls, 5 blue balls, and 6 green balls, suppose that they are selected one by one until a green ball is found.  what is the probability that it is necessary to examine at least 6 balls?\r<BR>\n" );
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document.write( "what i've tried.  obviously, there are 15 balls total, and by the combination formula, 15 nCr 6 (in TI-83 language, in English, 15 choosing 6) there are 5005 possible combinations when you choose 6 from a total of 15.  I am just stumped on how to get the numerator to divide by 5005.\r<BR>\n" );
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document.write( "Any insight would be greatly appreciated.  Thank you. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #364763 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=364763\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> another way to look at the question ___ what is the probability of drawing 5 consecutive non-green balls?\r<BR>\n" );
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document.write( "ways to draw 5 of 15 ___ 15C5\r<BR>\n" );
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document.write( "ways to draw 5 of 9 ___ 9C5\r<BR>\n" );
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document.write( "(9C5) / (15C5) </SPAN>\n" );
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