CEMC Cayley, 2001

Combinatorics Difficulty 2.0 Junior Find the answer Canada

The 6 members of an executive committee want to call a meeting. Each of them phones 6 different people, who in turn each calls 6 other people. If no one is called more than once, how many people will know about the meeting?

(A) $18$ (B) $36$ (C) $216$ (D) $252$ (E) $258$

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