document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1031741>Question 1031741</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a student takes an exam containing 12 true or false questions if the student guesses what is the probability that he will get exactly 2 questions right? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #646454 by </B><A HREF=/tutors/aboutme.mpl?userid=robertb><B>robertb(5830)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=robertb><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=robertb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=646454\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Choose any two out of the 12 questions, which can be done in C(12,2) = 66 ways.  (The only choice for each one of these is the correct answer.)  After doing this, for each of the remaining 10 incorrectly-answered questions, there are two choices, either the wrong answer or a no answer at all, which can be done in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%5E10+=+1024 ALIGN=MIDDLE  ALT=\"2%5E10+=+1024\"   DISABLED_style= \"max-width:90%; height:auto;\" > ways.\r<BR>\n" );
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document.write( "Therefore the probability is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28C%2812%2C2%29%2A2%5E10%29%2F3%5E12+=+%2866%2A1024%29%2F531441+=0.127 ALIGN=MIDDLE  ALT=\"%28C%2812%2C2%29%2A2%5E10%29%2F3%5E12+=+%2866%2A1024%29%2F531441+=0.127\"   DISABLED_style= \"max-width:90%; height:auto;\" >, to three significant figures. </SPAN>\n" );
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