Question

Identify each situation as a permutation or a combination.

1. choosing friends to invite to a party

2. choosing your top 10 favorite actors

Answer 1

1. Combination

2. Permutation

Explanation:

Permutations occur in cases where the order of something changes the arrangement (e.g. Choosing letters of a password). Combinations occur when the order of something does not matter (e.g. choosing three donut flavors).

1. Since the order of which you choose and invite your friends does not change who you've invited, this is a combination (order does not matter).

2. When ranking a top-10 list, the order of your ranking affects the ranking itself and makes a difference (order matters). Therefore, this situation is a permutation.