document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1190147>Question 1190147</A>: <I><SPAN STYLE=\"word-break: break-all;\"> ) A test consists of five questions, and to pass the<BR>\n" );
document.write( "test, a student has to answer at least four questions<BR>\n" );
document.write( "correctly.Each question has three possible answers,<BR>\n" );
document.write( "of which only one is correct. If a student guesses<BR>\n" );
document.write( "on each question, what is the probability that the<BR>\n" );
document.write( "student will pass the test ? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #821707 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=821707\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "(1) P(5 right)....<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281%2F3%29%5E5+=+1%2F243 ALIGN=MIDDLE  ALT=\"%281%2F3%29%5E5+=+1%2F243\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "(2) P(4 right)....<br><BR>\n" );
document.write( "(a) P(each one right) = 1/3; P(each one wrong = 2/3)<BR>\n" );
document.write( "(b) P(four right, one wrong, in a particular order) = (1/3)^4 times (2/3)^1 = 2/243<BR>\n" );
document.write( "(c) number of different choices for the one problem that is wrong = 5<br><BR>\n" );
document.write( "P(4 right) = 5 * 2/243 = 10/243<br><BR>\n" );
document.write( "P(pass test) = P(4 or 5 right) = 1/243+10/243 = 11/243<br><BR>\n" );
document.write( "ANSWER: 11/243<br>\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );