A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

ashleynguyenx3

  • one year ago

Probability: How many different permutations are there if you used 4 different digits? Repeat a digit?

  • This Question is Closed
  1. unknownunknown
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    4, 4^2, 4^3, 4^n.... n=repeats

  2. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Wouldn't it be 4 factorial?

  3. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Or is it different?

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

    That's if you want unique digits, then yes.

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

    Ahh I see what you mean. You take one out each time? So 4.. 3.. 2.. 1.. yes that's 4!.

  6. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Would it still be that if order matters?

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

    If you want certain digits in a specific order, then that would change it.

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

    Probability of selecting one digit from 4 is 0.25. Then 1 digit from 3 is 0.33, 1 digit from 2 is 0.5, 1 digit from 1 is 1. So the probability of doing all of that correctly is 0.25*0.33*0.5

  9. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I think I'm supposed to find the number or permutations not the probability, so I'm not completely sure.

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

    Then I'd go with 4!. Order wouldn't matter there.

  11. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay, so what about when we repeat a number?

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

    If we repeat, then instead of doing 4 * 3 * 2 *1, we have four digits still in each case. So we do 4 * 4 * 4 * 4 = 4^4 permutation

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

    By repeat, you mean we don't exclude the number we pick, right?

  14. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No this question is more for like iphone security codes. If that makes sense.

  15. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So that's why order matters.

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

    Okay, can you give me an example of two combinations then, that follow what you require.

  17. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So for 3 digits it would be like 123, 132, 213, 231, 321, 312 if there is no repeating

  18. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    With a repeating it would be 112, 121, 211

  19. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I know the one without repeating is 4!

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

    So for any two numbers a and b, a appears twice, and b once, in all three combinations. And do that for all numbers from 1 to 4?

  21. ashleynguyenx3
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yeah I think I found a site that might help

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

    Alright, good luck.

  23. 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.