document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1153647>Question 1153647</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi, I got stuck in a question:There are 5 Black balls, 4 red balls, and 1 blue ball in a bag. If 3 balls are drawn without replacement, find probability of:<BR>\n" );
document.write( "a) Exactly 1 black ball is drawn given that at least 1 black ball is drawn.<BR>\n" );
document.write( "For a), I have tried to use conditional probability, but I can't reach the value smaller than 1,and so here I am seeking for help, looking forward to your reply and thanks for your effort. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #775900 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=775900\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> probability of 1 black ball is 3*(5/10)(5/9)(4/8)=300/720=50/120, because 3 ways to choose<BR>\n" );
document.write( "that is (5C1)(5C2)/10C3=5*10/120=50/120 or 5/12<BR>\n" );
document.write( "for 2 it would be 3*5C2*5C1, which is the same <BR>\n" );
document.write( "for 3 it would be 5C3/10C3=10/120, or 1/12\r<BR>\n" );
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document.write( "Given that at least 1 (11/12 probability from adding the above)<BR>\n" );
document.write( "this would be (5/12)/(11/12)=5/11\r<BR>\n" );
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document.write( "to check, probability of no black balls being drawn is 5C0*5C3/10C3, which is 1/12 </SPAN>\n" );
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