document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=683010>Question 683010</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A new apartment complex advertises that it will give away three mopeds by a drawing from the first 80 students that sign a lease. Four friends are among the first 80 to sign. What is the probability that at least one of them will win a moped? (Round your answer to three decimal places.) Don't know how to do this at all! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #423430 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=423430\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This type of probability is usually solved by using the \"negative\" approach. That is, instead of trying to calculate the probability that 1,2,3 or 4 can win, calculate the probabability that NONE will win. This is<BR>\n" );
document.write( "(1) P(none win) = 76/80, that is, only the other 76 signers will win any of the 3 mopeds.<BR>\n" );
document.write( "Then the chances (probability) of at least one will win is <BR>\n" );
document.write( "(2) P(at least one wins) = 1 - 76/80 or<BR>\n" );
document.write( "(3) P(at least one wins) = 1/20 </SPAN>\n" );
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