Question 617678: I asked a question a few weeks ago: How many ways can 4 people be chosen from a group of 9. permutation or combination?
Please help. Thank you very much
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!
Depends. Does order matter? For instance, if you had a club with 9 members and you wanted to pick a President, Vice-President, Secretary, and Treasurer, then Bob, Sally, George, Ringo is different from Sally, Ringo, George, Bob. But if from the same club you just wanted to pick a 4 person committee, then Bob, Sally, George, Ringo is the same as Sally, Ringo, George, Bob or Ringo, George, Bob, Sally or any of the 21 other ways to order 4 things.
If order matters: Permutation. \ =\ \frac{n!}{(n\,-\,r)!})
If order does not matter: Combination. !})
Notice that the two differ by a factor of  which puts the number of ways to arrange  things in the denominator of the combination calculation, making the permutation calculation larger by a factor of  .
John
My calculator said it, I believe it, that settles it
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