document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=418209>Question 418209</A>: <I><SPAN STYLE=\"word-break: break-all;\"> It is known that 60% of riders on motor bikes wear helmets.The traffic police randomly looking for riders on motor bikes not wearing a helmet observe 5 riders on motor bikes.<BR>\n" );
document.write( "a)Find the probability that he finds that every one of the riders was wearing a helmet.<BR>\n" );
document.write( "b) Find the probability that at least two  of the riders were wearing helmets.<BR>\n" );
document.write( "c)What is the expectation of number of riders out of 5 riders wearing helmets? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #292743 by </B><A HREF=/tutors/aboutme.mpl?userid=edjones><B>edjones(8007)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=edjones><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=edjones><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=292743\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> p=.6, q=.4<BR>\n" );
document.write( "(p+q)^5=p^5+5p^4q+10p^3q^2+10p^2q^3+5pq^4+q^5<BR>\n" );
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document.write( "a) p^5=.6^5=.07776  probability that he finds that every one of the riders was wearing a helmet.<BR>\n" );
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document.write( "b) 1-(5pq^4+q^5)=1-(.0768+.01024)=.91296 probability that at least two  of the riders were wearing helmets.<BR>\n" );
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document.write( "c) 5*.6=3 expectation of number of riders out of 5 riders wearing helmets.<BR>\n" );
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document.write( "Ed </SPAN>\n" );
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