Answer:
at least 5
Explanation:
If the question was similar to the one given below
A researcher plans to identify each participant in a certain medical experiment with a code consisting of either a single letter or a pair of distinct letters written in alphabetical order. What is the least number of letters that can be used if there are 12 participants, and each participant is to receive a different code?
The answer would be as follows
If we use 3 letters or any distinct letter as a comma such that 2 are in alphabetical order then we would get
4C2= 6 ways to use these letters and the comma
If we use 4 letters or any distinct letter as a comma such that 2 are in alphabetical order then we would get
5C2= 10 ways to use these letters and the comma
If we use 5 letters or any distinct letter as a comma such that 2 are in alphabetical order then we would get
6C2= 15 ways to use these letters and the comma
We need the least number of the alphabets to assign codes to 12 participants.
So the least number of alphabets is 5 because it can give codes to at least to 12 people .
Pair of alphabets + distinct letter ≥ 12
5 + 1 ≥ 12
6c2 ≥ 12
15 ≥ 12