document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1180651>Question 1180651</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 3.	A sample of 4 different calculators is randomly selected from a group containing 13 that are defective and 26 that have no defects. What is the probability that at least one of the calculators is defective? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #810403 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=810403\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the probability none is defective<BR>\n" );
document.write( "There are 39C4 ways to take the sample<BR>\n" );
document.write( "For no defective ones, there are 26C4 possibilities <BR>\n" );
document.write( "so the answer is 1-26C4/39C4<BR>\n" );
document.write( "1-0.1818=0.8182\r<BR>\n" );
document.write( "\n" );
document.write( "can check<BR>\n" );
document.write( "prob of 1 is 13C1*26C3/39C4<BR>\n" );
document.write( "=0.4109<BR>\n" );
document.write( "-<BR>\n" );
document.write( "for 2 it is 13C2*26C2/39C4<BR>\n" );
document.write( "=0.3082<BR>\n" );
document.write( "-<BR>\n" );
document.write( "for 3 it is 13C3*26C1/39C4<BR>\n" );
document.write( "=0.0904<BR>\n" );
document.write( "-<BR>\n" );
document.write( "for 4 it is 13C4/39C4<BR>\n" );
document.write( "=0.0087 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );