one-, two-, or three-letter code

[ska7945]

A certain stock exchange designates each stock with a one-, two-, or three-letter code, where each letter is selected from the
26 letters of the alphabet. If the letters may be repeated and if the same letters used in a different order constitute a different code, how many different stocks is it possible to uniquely designate with these codes?

(A) 2,951
(B) 8,125
(C) 15,600
(D) 16,302
(E) 18,278

[vittalgmat]

I think this was already discussed.. pls search prev posts.
I think u will see this discussed within last 50 posts.

rgds
-V

[cramya]

https://www.beatthegmat.com/alphabet-cod ... t6108.html