Revision as of 21:35, 9 November 2013 by Fadebekun(talk | contribs)(Created page with "==Problem== When <math>\left ( 1 - \frac{1}{a} \right ) ^6</math> is expanded the sum of the last three coefficients is: <math> \textbf{(A)}\ 22\qquad\textbf{(B)}\ 11\qquad\text...")