document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1020101>Question 1020101</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A box contains 7 white balls and 6 red balls.  If Van chooses 9 balls at random from the box, what is the probability that he will select 4 white balls and 5 red balls?\r<BR>\n" );
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document.write( "I had tried 7/9 X 6/8 ,  4/7 X 5/6.  Also tried (7/9)^2  X (6/8)^2....the answer is supposed to be .294, but I can't get that.   Thanks  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #636109 by </B><A HREF=/tutors/aboutme.mpl?userid=richard1234><B>richard1234(7193)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richard1234><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=richard1234><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=636109\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You are randomly guessing. Please review the nCr operator (the binomial coefficient, i.e. n choose r). Otherwise you will be lost in this solution.\r<BR>\n" );
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document.write( "Here, we will assume the balls are distinguishable. How many ways can you choose 9 balls from a box containing 13 balls? The number of such ways is 13C9 (\"13 choose 9\") = 13!/9!*4! = 715. \r<BR>\n" );
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document.write( "Now you want the number of ways Van can choose exactly 4 white and 5 red balls. The number of ways is 7C4 * 6C5 = 35*6 = 210.\r<BR>\n" );
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document.write( "The probability is 210/715 = 0.2937... </SPAN>\n" );
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