document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=603486>Question 603486</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A pair of dice is rolled three times. Find the probability that at least two sums are 7.<BR>\n" );
document.write( "I am trying to figure out if I should use combinations or not and how to consider that it says at least. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #380726 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=380726\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> this is a binomial probability ___ either 7 or not 7\r<BR>\n" );
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document.write( "there are 6 ways to get 7 out of 36 possible outcomes ___ so the probability of 7 (on any roll) is 6/36 or 1/6<BR>\n" );
document.write( "___ P(s) = 1/6 , P(n) = 5/6\r<BR>\n" );
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document.write( "the expansion is ___[P(s) + P(n)]^3 = s^3 + 3s^2n + 3sn^2 + n^3\r<BR>\n" );
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document.write( "at least two means the sum of the first two terms (with s^3 and s^2)\r<BR>\n" );
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document.write( "P = (1/6)^3 + [3 * (1/6)^2 * (5/6)] </SPAN>\n" );
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