document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1046226>Question 1046226</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The probability that traffic lights on a certain road will be green is 0.6. When a driver on that road approaches two traffic lights in a row, X is the number of traffic lights that are green.\r<BR>\n" );
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document.write( "What is P(X=1) as a decimal? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #661871 by </B><A HREF=/tutors/aboutme.mpl?userid=robertb><B>robertb(5830)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=robertb><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=robertb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=661871\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> There are only three possible mutually exclusive cases here:\r<BR>\n" );
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document.write( "{red},<BR>\n" );
document.write( "{green, red}, and <BR>\n" );
document.write( "{green, green}.\r<BR>\n" );
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document.write( "These can be illustrated also using a tree diagram.\r<BR>\n" );
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document.write( "P({red}) = 0.4,<BR>\n" );
document.write( "P({green, red}) = 0.6*0.4 = 0.24, and <BR>\n" );
document.write( "P({green, green}= = 0.6*0.6 = 0.36.\r<BR>\n" );
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document.write( "P(X=1) = P({green, red}) = 0.24. </SPAN>\n" );
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