Permutation or Combination
A baseball team has 13 members. If a batting line-up consists of 9 players, how many different batting line-ups are possible?
The answer in my textbook for this question uses permutations to derive the answer.. However, I believe that it's wrong.. you should be using combinations to find the answer. I think combinations because in this question, its asking for a line-up of batting players.. in this case, order doesn't matter.. Does it?
Also, just another side question:
if a question is talking about a sports team.. would it be a permutation or combination? I think it's combinations for sports teams.. but then this question with the baseball team makes me think otherwise.. But what's really right? should it be combinations or permutations for any sports team q?