document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=977814>Question 977814</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I've run into a road block with Combinatorial Probability. I did the first two questions on my homework fine, I think the idea here is to add a step. Do not know what the next step is (meaning, the material is progressively more difficult). I computed previously leading to the n!/r!(n-r)!.\r<BR>\n" );
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document.write( "3. There are 27 tasks available. You will be randomly assigned 12 of them. There are 10<BR>\n" );
document.write( "of them that you want to do.<BR>\n" );
document.write( "(a) What is the probability that you will be assigned none of the tasks that you want?<BR>\n" );
document.write( "(b) What is the probability that you will be assigned exactly 7 of the tasks that you<BR>\n" );
document.write( "want?<BR>\n" );
document.write( "(c) What is the probability that you will be assigned at least 1 of the tasks that you<BR>\n" );
document.write( "want?<BR>\n" );
document.write( "(d) What is the probability that you will be assigned at least 7 of the tasks that you<BR>\n" );
document.write( "want?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #599373 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=599373\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "Part a)  There are 10 tasks that you want to do, so there are 17 tasks you don't want to do.\r<BR>\n" );
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document.write( "The probability of being assigned, for the first assignment, a task you don't want to do is then <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \frac{17}{27}\">\r<BR>\n" );
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document.write( "Then, based on the assumption that you actually received a \"don't want to do\" task for the first assignment, then you now have 16 tasks left that you don't want to do out of a total of 26 tasks, hence <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \frac{8}{13}\">\r<BR>\n" );
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document.write( "Then, <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \frac{3}{5}\">\r<BR>\n" );
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document.write( "Then, <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \frac{7}{12}\">\r<BR>\n" );
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document.write( "And so on for 17 factors.  The combined probability is the product of all 17 factors.\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi}\ +\ 1\ =\ 0\"><BR>\n" );
document.write( "My calculator said it, I believe it, that settles it\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \ \\r\"> </SPAN>\n" );
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