A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

nincompoop

  • one year ago

what is a permutation?

  • This Question is Closed
  1. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    permutation < -- order matters combination <-- order doesn't matter

  2. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    it's like a license plate. only the first spot can occupy the letter A

  3. nincompoop
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    let us provide an example that uses fundamental counting principle

  4. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Two types of permutation Permutation with repetition A combination lock. It can be 222 Permutation without repetition You're competing at a track and field race. You can only be first,second or third. You can't occupy first and second at the same time

  5. nincompoop
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i.e. List all permutations of the letters in the word CAT.

  6. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    that's just a three letter word.

  7. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    wait... three letters... that's 3 x 3 x 3 = 27 if we allow those letters to be repetitive though.

  8. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    but there's no CCAT or anything like that .. that would be 4!/2!

  9. nincompoop
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so without repetition, we have: \(3 \times 2 \times 1 \) since we have 3 letters, which corresponds to 3 events. Meaning in our first event, it does not matter if we picked C, A or T. Then for our second event, we have only 2 letters left, because we exclude the first event that occurred; then it follows that we have one event left for the third event.

  10. nincompoop
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    without repetition: \(\large _nP_n \): number of permutations of "n" things taken "n" at a time. \(\large _nP_n = n! \)

  11. nincompoop
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    20 people are running for an office in an election. In how many ways can you choose a President (P), Vice President (VP), and Secretary (S).

  12. nincompoop
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \(\sf P:20; VP: 19; S:18\) \(20 \times 19 \times 18 = 6840\) Permutations of "n" elements taken "r" at a time. \(\large _nP_r = \frac{n!}{(n-r)!} = \frac{20!}{(20-3)!} = 6840 \)

  13. nincompoop
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The 7-digit phone numbers in a city all have 661 as the first three digits. How many different phone numbers are possible?

  14. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.