document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1130970>Question 1130970</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Printed circuit cards are placed in a functional test after being populated with semiconductor chips. A lot contains 21 cards, and 4 are selected without replacement for functional testing.\r<BR>\n" );
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document.write( "(Please enter your answers as fractions in lowest terms or as decimals rounded to four decimal places. Thank you!)\r<BR>\n" );
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document.write( "a. If 15 cards are defective, what is the probability that at least one defective card is in the sample?\r<BR>\n" );
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document.write( "b. If 14 cards are defective, what is the probability that at least one defective card is in the sample? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #749340 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=749340\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find probability no defective cards are and subtract from one.<BR>\n" );
document.write( "(6/21)(5/20)(4/19)(3/18)=(2/7)(1/4)(4/19)(1/6)=2/798=1/399<BR>\n" );
document.write( "398/399 is the probability at least one card is defective.\r<BR>\n" );
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document.write( "(7/21)(6/20)(5/19)(4/18)=(1/3)(3/10)(5/19)(2/9)=1/171<BR>\n" );
document.write( "so the probability is 1-1/171 or 170/171\r<BR>\n" );
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