By definition:
• a, combination, is a mathematical technique that determines the number of possible arrangements in a collection of items where the order of the selection does not matter. ,In combinations, you can select the items in any order,.
• in ,permutations,, the order of the selected items is essential,. For example, the arrangements ab and ba are equal in combinations (considered as one arrangement), while in permutations, the arrangements are different.
From the list of examples we see that:
A) We select a president and a vice president, so order matters → permutation.
B) The order of the numbers of a lock's key matters → permutation.
C) The order of the members of the team doesn't matter → combination.
D) The order of the letter matters → permutation.
Answer: C