document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=421808>Question 421808</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A multiple choice exam has ten questions and each question had 4 possible answers.  In each case only 1 of the 4 possibilities is correct.  Billy fills out an answer sheet by simply guessing without even reading the questions.  What is the probability that he will get 100% on the exam?   What is the probability that he will get 90% on the exam?   What is the probability that he will get at leat an 80% on the exam?   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #294481 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=294481\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A multiple choice exam has ten questions and each question had 4 possible answers. In each case only 1 of the 4 possibilities is correct. <BR>\n" );
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document.write( "Billy fills out an answer sheet by simply guessing without even reading the questions.<BR>\n" );
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document.write( "Binomial with n = 10 and p = 1/4<BR>\n" );
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document.write( "What is the probability that he will get 100% on the exam? <BR>\n" );
document.write( "P(x = 10) = (1/4)^10 = 9.5367x10^-7<BR>\n" );
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document.write( "What is the probability that he will get 90% on the exam? <BR>\n" );
document.write( "P(x = 9) = 10C9*0.25^9*0.75 = 2.8610x10^-5<BR>\n" );
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document.write( "What is the probability that he will get at least an 80% on the exam?<BR>\n" );
document.write( "P(x = 8) = 10C8*0.25^8*0.75^2 = 3.8624x10^-4<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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