What letter must replace the "(?)" in this finite sequence? Explain.

A, A, A, A, (?), A, A, A, A, A, A, __, __, __, __, __, __, A, __, ... , A.

Hint:
All "A"s are present, and the last "A" shown is the final letter of the sequence.

(In reply to re: Not quite a guess. by brianjn)

When I first saw the letter "A", I thought it was a play on numbers with base greater than 10.  But the series is finite.  And it ended around 21+ elements in the sequence.  While thinking about the letters of the alphabet I shifted to the greek alphabet.
alphA, betA, gammA, deltA, epsiloN, . . .

I did not know if the answer was the earliest letter (C is earlier than D or E) in the name or the last letter of the name.  What solved it for me was that the 19th letter "Tau" has an A but is not listed as one of the A's in the sequence.  Thus it was the last letter in the name.

The fifth letter of the greek alphabet is epsiloN, and its last letter and the answer to the problem is "N".

The "not J" was a small hint - there is no J in the greek alphabet.

Posted by Leming on 2008-08-24 23:57:59