A) 14
B) 20
C) 28
D) None of these
Correct Answer: B
Solution :
[b] From n points number of hexagon is \[^{n}{{C}_{6}}=\frac{n!}{\{(n-6)!\}\{6!\}}\] From n points numbers of octagons is \[^{n}{{C}_{8}}=\frac{n!}{\{(n-8)!\}\{8!\}}\] Ratio of number of hexagon to number of octagon is \[\frac{\{(n-8)!\}\{8!\}}{\{(n-6)!\}\{6!\}}=\frac{7\times 8}{(n-7)(n-6)}=\frac{4}{13}\] On solving this quadratic equation we will get \[n=20\]
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