Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

catgirl17

you own 9 pairs of jeans and are taking 4 of them on vacation. in how many ways can you choose 4 pairs of jeans from the 9?

  • one year ago
  • one year ago

  • This Question is Closed
  1. Ledah
    Best Response
    You've already chosen the best response.
    Medals 0

    Seeing as this is probability I'm going to say that there are 36 or 45 choices on pants you can pick. hope this helps.. there are so many ways you can do this

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

    9c4

    • one year ago
  3. mathplane
    Best Response
    You've already chosen the best response.
    Medals 1

    This is an example of a combination problem... First, establish how many ways there are to pack the jeans.... There are 9 choices for the 1st pair of pants... 8 remaining choices for the 2nd pair... 7 remaining for the 3rd pair... And, 6 remaining choices for the 4th pair.... this implies 9 x 8 x 7 x 6 permutations.... However, ORDER DOES NOT MATTER.. Therefore, we must divide to get rid of all the "double counting"... (i.e. choosing 1469 pants is the same as 4169 or 9146... in each case, you packed 1-4-6-9...)... So, your final solutions is (9 x 8 x 7 x 6)/(4!) = 126

    • one year ago
  4. mathplane
    Best Response
    You've already chosen the best response.
    Medals 1

    Using the formula for combinations: 9C4 = 9!/5!4! = 126

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

    Totally thought of something else.......

    • one year ago
  6. catgirl17
    Best Response
    You've already chosen the best response.
    Medals 0

    how did you get 126?

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

    Thats what I'm wondering

    • one year ago
  8. catgirl17
    Best Response
    You've already chosen the best response.
    Medals 0

    cause when you do 9x8x7x6=3024 and then if you divide it by 4 you get 756

    • one year ago
  9. mathplane
    Best Response
    You've already chosen the best response.
    Medals 1

    No, you must divide by 4! 3024/24

    • one year ago
  10. catgirl17
    Best Response
    You've already chosen the best response.
    Medals 0

    where did you get 24 from?

    • one year ago
  11. mathplane
    Best Response
    You've already chosen the best response.
    Medals 1

    4! = 4 x 3 x 2 x 1 = 24

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

    The exclamation mark isn't yelling, it's called a factorial :) so N! would be N multiplied by all the numbers that come before it

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

    Just fyi

    • one year ago
    • Attachments:

See more questions >>>

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.