document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=171110>Question 171110</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A teacher will take 10 questions from a study guide of 20 questions for a quiz.  If a student knows the answer to 15 of the questions, what is the probability that student will get:\r<BR>\n" );
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document.write( "all 10 questions correct?<BR>\n" );
document.write( "exactly 8 questions correct?<BR>\n" );
document.write( "at least 9 questions correct?\r<BR>\n" );
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document.write( "I was able to solve the first question, the answer being (21/1292) by evaluating 15(nCr)10 / 20(nCr)10, but I have no idea how to do the other two questions.  Even after I was given the answers, I couldn't figure out how to get to them.\r<BR>\n" );
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document.write( "Answer to second one is (225/646)<BR>\n" );
document.write( "Answer to third one is (49/323)\r<BR>\n" );
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document.write( "Please Help! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #126338 by </B><A HREF=/tutors/aboutme.mpl?userid=oscargut><B>oscargut(2103)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=oscargut><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=oscargut><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=126338\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 2nd) P(8 correct) is  (15(nCr)8)(5(nCr)2)  / 20(nCr)10<BR>\n" );
document.write( "3rd) P(at least 9)=P(9 correct)+P(10 correct)<BR>\n" );
document.write( "=[(15(nCr)9)(5(nCr)1)+ (15(nCr)10)] / 20(nCr)10 </SPAN>\n" );
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