11. Write a few sentences explaining how you can distinguish a question about permutations from a question about combinations.

Whenever the position matters, use permutation.

If position does not matter, then it's a case of combination.

Step-by-step explanation:

Consider the provided information.

Whenever the position matters, use permutation.

For example: If (X, Y) and (Y, X) are different, it is a permutation question.

In Permutations every small detail matters.

For example: David, John and Stuart is different from John, David, and Stuart (As the order is different).

If position does not matter, then it's a case of combination.

For example: (X, Y) is the same as (Y, X), It is a combination question.

In Combinations the small details don't matter.

For example: David, John and Stuart is not different from John, David, and Stuart.