document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=286162>Question 286162</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A student takes a true-false test consisting of 13 questions. Assuming that the student guesses at each question, find the probability that the student answers exactly 11 questions correctly. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #207653 by </B><A HREF=/tutors/aboutme.mpl?userid=edjones><B>edjones(8007)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=edjones><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=edjones><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=207653\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> t=.5 and f=.5<BR>\n" );
document.write( "We could expand the binomial (t+f)^13 and get the term t^11f^2<BR>\n" );
document.write( "Combination=nCr=13C11=78 coefficient of the number.<BR>\n" );
document.write( "78*.5^11*.5^2<BR>\n" );
document.write( "=.0095 the probability that the student answers exactly 11 questions correctly.<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Ed </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );