document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=132069>Question 132069</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There are 20 questions in a multiple-choice test.  Each question has five choices and one correct answer out of these five choices.   A student did not study.  He/she answers the questions at random  What are the probabilities that he/she makes (i) more than 10-answers right?  (ii) exatly eight right? And (iii) at most 7 right? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #96450 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=96450\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> There are 20 questions in a multiple-choice test. Each question has five choices and one correct answer out of these five choices. A student did not study. He/she answers the questions at random What are the probabilities that he/she makes \r<BR>\n" );
document.write( "\n" );
document.write( "(i) P(more than 10-answers right) = 1-binomcdf(20,(1/5),10) = 0.0005634 <BR>\n" );
document.write( "(ii) P(exactly eight right) = binompdf(20,5^-1,8) = 0.0222...<BR>\n" );
document.write( "(iii) P(at most 7 right) = binomcdf(20,5^-1,7) = 0.9679..<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );