Question

Construct a list as requested:

Let N = {S, P, O, M}. List all of the ways that you can select two different members of N. The order in which you select the members is not important.

A
SP, SO, SM, PS, PO, PM, OS, OP, OM, MS, MP, MO

B
SP, SO, SM, PO, PM, OM

C
SS, SP, SO, SM, PP, PS, PS, PM, OO, OS, OP, OM, MM, MS, MP, MO

D
SS, SP, SO, SM, PP, PO, PM, OO, OM, MM

Answer 1

Is it C?

Answer 2

2^4?

Answer 3

two different
why it isn't A?

Answer 4

I think it is A
\[C_{2}^{4}=12\]