document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=665650>Question 665650</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A pen holder holds ten pens, three of which do not write. If three pens are selected at random, find the probability that at least one (a)writes and (b) doesnt write? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #413984 by </B><A HREF=/tutors/aboutme.mpl?userid=DrBeeee><B>DrBeeee(684)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=DrBeeee><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=413984\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I'm not an expert on this, but I'll give you an answer and maybe one of the other tutors can comment/correct it.<BR>\n" );
document.write( "I say that the<BR>\n" );
document.write( "(1) P(at least one writes) = 1 - P(none write) or<BR>\n" );
document.write( "(2) P(at least one writes) = 1 - (3/10)(2/9)(1/8)<BR>\n" );
document.write( "(3) P(at least one writes) = 119/120<BR>\n" );
document.write( "The<BR>\n" );
document.write( "(4) P(at least one doesn't write) = 1 - P(all write)<BR>\n" );
document.write( "(5)    ditto                      = 1 - (7/10)(6/9)...(1/4)<BR>\n" );
document.write( "(6) P(at least one doesn't write) = 119/120<BR>\n" );
document.write( "Sorry, no guarantees.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );