Answer:
N = 4C2
N = 6 ways
List of samples;
1. A,B
2. A,C
3. A,D
4. B,C
5. B,D
6. C,D
Step-by-step explanation:
Since the order is not relevant, this is a combination case.
nCr = n!/r!(n-r)!
We are to select two letters from A,B,C,D (2 from 4)
The number of possible selections N can be given as:
N = 4C2 = 4!/2!(4-2)! = 4!/2!2! = 6
N = 6 ways
List of samples;
1. A,B
2. A,C
3. A,D
4. B,C
5. B,D
6. C,D
