document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=394616>Question 394616</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose that after 10 years of service, 40% of computers have problems with motherboards (MB), 30% have problems with hard drive (HD), and 15% have problems with both MB and HD. What is the probability that a 10-year old computer still has fully functioning MB and HD? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #280057 by </B><A HREF=/tutors/aboutme.mpl?userid=jrfrunner><B>jrfrunner(365)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jrfrunner><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=jrfrunner><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=280057\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let MB=prob with motherboards<BR>\n" );
document.write( "let HD problems with hard drive\r<BR>\n" );
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document.write( "P(problems with MB or HD)=P(MB U HD)=P(MB)+P(HD)-P(MB n HD)=0.4+.3-.15=.7-.15=.55<BR>\n" );
document.write( "--<BR>\n" );
document.write( "This means that P(no MB or HD)= 1-0.55=0.45 </SPAN>\n" );
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