document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=948396>Question 948396</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If P(A) = 0.5, P(AandB) = 0.3, and P(AorB) = 0.6, find P(B).<BR>\n" );
document.write( "-------------------------------------------------------<BR>\n" );
document.write( "A an B are independent events. P(A) = 0.3, and P(A or B) = 0.8. Find P(B).  The more I see, the more I get confused.  <BR>\n" );
document.write( "Thanks in advance. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #578873 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=578873\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If P(A) = 0.5, P(AandB) = 0.3, and P(AorB) = 0.6, find P(B).\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "P(A or B) = P(A) + P(B) - P(A and B)<BR>\n" );
document.write( "0.6 = 0.5 + P(B) - 0.3<BR>\n" );
document.write( "0.6 = 0.2 + P(B)<BR>\n" );
document.write( "0.6 - 0.2 = P(B)<BR>\n" );
document.write( "0.4 = P(B)<BR>\n" );
document.write( "P(B) = 0.4\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "-------------------------------------------------------\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "A an B are independent events. P(A) = 0.3, and P(A or B) = 0.8. Find P(B).  \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "x = P(B)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "\"A an B are independent events\" so P(A and B) = P(A)*P(B)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "P(A or B) = P(A) + P(B) - P(A and B)<BR>\n" );
document.write( "P(A or B) = P(A) + P(B) - P(A)*P(B)<BR>\n" );
document.write( "0.8 = 0.3 + x - 0.3*x<BR>\n" );
document.write( "0.8 = 0.3 + 0.7*x<BR>\n" );
document.write( "0.8 - 0.3 = 0.7*x<BR>\n" );
document.write( "0.5 = 0.7*x<BR>\n" );
document.write( "0.5/0.7 = x<BR>\n" );
document.write( "5/7 = x<BR>\n" );
document.write( "x = 5/7<BR>\n" );
document.write( "x = 0.71429 (this is approximate)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "P(B) = 5/7 which is approximately 0.71429 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );