Assume that 3 customers arrive and order different appetizers from a choice of 12 how many possible ways can this be done is it permutation or combination?

Permutation would be used if the order in which the customers arrived mattered, but in this case, it does not. So, we use combinations to determine the number of possible ways that 3 customers can order different appetizers from a choice of 12.

The formula for combinations is:

```

C(n, r) = n! / (n - r)! / r!

```

where:

* n is the total number of items (in this case, the total number of appetizers)

* r is the number of items to be chosen (in this case, the number of appetizers that each customer orders)

Plugging in the values we have:

```

C(12, 3) = 12! / (12 - 3)! / 3!

C(12, 3) = 12! / 9! / 3!

C(12, 3) = 12 x 11 x 10 / 3 x 2 x 1

C(12, 3) = 220

```

Therefore, there are 220 possible ways that 3 customers can order different appetizers from a choice of 12.