1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Counting problem (aabbcccdddd)

  1. Apr 1, 2005 #1
    hi everyone....
    how many arrangements of this word "aabbcccdddd" is possible if we only use 3 of them? I know if we could use all of them it would just be 11!/(2!2!3!4!), but what if we only use 3? :confused:

    Thanks in advance
     
  2. jcsd
  3. Apr 1, 2005 #2
    I assume you mean 3 letters in the arrangement. First count the number of ways to permute using 1 letter of each, then in addition to that count the number of ways to permute using 1 of one letter and 2 of another, and then add 2 for the arrangements ccc and ddd.
     
  4. Apr 1, 2005 #3
    ok..thanks...so the answer would be 52?
     
  5. Apr 1, 2005 #4
    Not quite what I got--maybe you added wrong at the end?
     
  6. Apr 2, 2005 #5
    umm...i tried it again...i got 62 (checked it 3 times!)
     
  7. Apr 2, 2005 #6
    Yep, 62 is what I got. You said 52 the other time.
     
  8. Apr 2, 2005 #7
    thanks a lot
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Counting problem (aabbcccdddd)
  1. Counting Problems (Replies: 2)

Loading...