A) 72
B) 153
C) 306
D) 2556
Correct Answer: B
Solution :
Given that \[^{n}{{C}_{12}}={{\,}^{n}}{{C}_{6}}\] or \[^{n}{{C}_{n}}={{\,}^{n}}{{C}_{6}}\] \[\Rightarrow \] \[n-12=6\,\,\,\,\,\Rightarrow \,\,\,\,\,n=18\] \[\therefore \] \[^{n}{{C}_{2}}={{\,}^{18}}{{C}_{2}}=\frac{18\times 17}{2\times 1}\] \[=153\]You need to login to perform this action.
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