document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1188688>Question 1188688</A>: <I><SPAN STYLE=\"word-break: break-all;\"> It is known from the past experience that 80% of the students in a school do their home work. Find the probability  that during a random check of 10 students  a)all have done their home work  b) at the most two students have not done their home work  c)at least one student has done the home work. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #819839 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=819839\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> All have done it is 0.8^10 (independent)=0.1074<BR>\n" );
document.write( "at most two have not done it.<BR>\n" );
document.write( "0 have not done it is 0.1074<BR>\n" );
document.write( "1 has not done it is 10*0.8^9*0.2^1=0.2684<BR>\n" );
document.write( "2 have not done it is 10C2*0.8^8*0.2^2=0.3020<BR>\n" );
document.write( "That sum and the answer is 0.6778<BR>\n" );
document.write( "-<BR>\n" );
document.write( "At least 1 student has done it is 1- nobody has done it which is probability  <0.0001 (1 x 10^(-7)) or 0.2^10<BR>\n" );
document.write( "so the answer is 1.000. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );