document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=238550>Question 238550</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How do u do these questions:\r<BR>\n" );
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document.write( "A lot contains 12 items of which 4 are defective. Three items are drawn at random from the lot one after the other. Find the probability p that all three are non-defective. \r<BR>\n" );
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document.write( "A man visits a couple who have two children. One of the children, a boy, comes into the room. Find probability p that the other is also a boy if (i) the other child is known to be younger (ii) nothing is known about the other child.   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #175304 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=175304\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> How do u do these questions: <BR>\n" );
document.write( "A lot contains 12 items of which 4 are defective. Three items are drawn at random from the lot one after the other. Find the probability p that all three are non-defective.<BR>\n" );
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document.write( "# of ways to get 3 non-defective = 8C3 = (8*7*6)(1*2*3) = = 56<BR>\n" );
document.write( "# of ways to get 3 unrestricteded = 12C3 = (12*11*10)/(1*2*3) = 220<BR>\n" );
document.write( "P(3 non) = 56/220 = 0.2545<BR>\n" );
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document.write( "A man visits a couple who have two children. One of the children, a boy, comes into the room. Find probability p that the other is also a boy if (i) the other child is known to be younger <BR>\n" );
document.write( "Age has nothing to do with it; neither does the fact that the 1st child<BR>\n" );
document.write( "to appear is a boy.<BR>\n" );
document.write( "The answer is 1/2<BR>\n" );
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document.write( "(ii) nothing is known about the other child.<BR>\n" );
document.write( "It's still 1/2<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
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