document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=529901>Question 529901</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There are three urns that each contain 10 balls. The first contains 3 white balls and 7 red balls, the second 8 white and 2 red, and the third all 10 white. Each urn has an equal probability of being selected. After an urn is selected a ball is randomly drawn from this urn. If the ball drawn was white, find the probability that the third urn was selected. (Round your answer to three decimal places.) <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #349919 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=349919\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> there are 21 white balls\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "10 of them are in the 3rd urn\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if a white ball is drawn, the probability is 10/21 that it came from the 3rd urn </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );