document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1035080>Question 1035080</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a school 70 percent have math class 65 percent have science class and 45 percent have math and science what's the probability that a random selected student will have science this semester given they already have a math class this semester  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #649700 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=649700\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> p(a given b) = p(a and b) / p(b)\r<BR>\n" );
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document.write( "p(a) = probability student takes a math class.<BR>\n" );
document.write( "p(b) = probability student takes a science class.<BR>\n" );
document.write( "p(a and b) = probability student takes both a math class and a science class.\r<BR>\n" );
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document.write( "since 70% take math, then p(a) = .70<BR>\n" );
document.write( "since 65% take science, then p(b) = .65<BR>\n" );
document.write( "since 45% take both, then p(a and b) = .45\r<BR>\n" );
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document.write( "p(a given b) becomes .45 / .70 = .6428571429.\r<BR>\n" );
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document.write( "that's the probability that a randomly selected student will take science given that he takes math.\r<BR>\n" );
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document.write( "assume 45 students take math and science.<BR>\n" );
document.write( "assume 25 students take math only.<BR>\n" );
document.write( "assume 20 students take science only.\r<BR>\n" );
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document.write( "total number of students is 90 that take either math or science.\r<BR>\n" );
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document.write( "out of that 90, 70 take either math or math and science.<BR>\n" );
document.write( "that's 25 for math only and 45 that take math and science.<BR>\n" );
document.write( "so, out of the 70 who take math, 45 also take science.<BR>\n" );
document.write( "that'a a percentage of 45/70 = .6428571429 = approximately 64.29%.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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