Answer:
There are 16276 different stocks which are possible to uniquely designate with these codes
Step-by-step explanation:
The information we have is that
1. There are 26 different letters.
2. The stock can be designated with a one, two or three letter code and the letters may be repeated (We always have 26 options for the first, second and third letter)
3. Order matters (different order constitute a different code), which means we're talking about permutations.
The total codes we can make would be:
[tex]P_{26|1} + P_{26|2}+ P_{26|3} \\26+650+15600= 16276[/tex]