1. A

    combination with repetition

    Hi, I can't figure out how to solve this: Sum (i=0 --> n-1) (p+i)!/(p!*i!) = (n+p)!/((n-1)!*(p+1)!) thanks in advance! Alome
  2. G

    Combinations with repetition (I think)

    Long time no see... My greetings to all forum users. I know that if we havek identical sets that each one of them has n objects and we want to pick $k$ objects, one from each set, how many combinations do we have? The formula is (stars and bars approach): CC(n,k)=\dfrac{(n+k-1)!}{k!(n-1)!} For...
  3. M

    Repetition with Permutations-Number of Routes on a Grid Help?

    How many routes are possible from A to B in this diagram: Untitled photo by MightyOwned | Photobucket I know it's a crap paint diagram. But you get the idea. The answer is apparently 600. I tried doing 5!/(3!2!) X 6!/(3!3!) + 5!/(3!2!) X 6!/(4!2!) but no luck. Please help.
  4. J

    Permutations with Repetition help (2 Questions)

    Here are 2 problems I am currently stuck on. A) In the card game for bridge, 2 cards are dealt to 4 people who are called North, South, East and West. A 52 letter "word" consisting of 13 N's, 13 S's, 13 E's and 12 W's will tell you who has what card. For example, if a word begins with...
  5. S

    Combinations removing duplications and repetition

    Is there a general formula which can tackle the following: given n objects and r spots, I want to calculate the number of possible combinations accounting for duplicates and repetition. eg. n = 4, r = 3 (AAAB) possible combinations: AAA AAB result is 2 eg. n = 4, r = 3 (AABC) possible...
  6. mybrohshi5

    Combination with repetition

    8 identical blackboards are divided among 4 schools: 1) what are the # of divisions possible? using combination with repetition formula \binom{n+k-1}{n-1} I get \binom{8+4-1}{4-1} = \binom{11}{3} 2) how many divisions are possible if each school receives at least 1 blackboard...
  7. L

    r-Combinations with Repetition Allowed

    Another way to count the number of nonnegative integral solutions to an equation of the form x1+x2+...+xn=m is to reduce the problem to one of finding the number of n-tuples (y1,y2,...,yn) with 0<=y1<=y2<=...<=yn<=m. The reduction results from letting yi=x1+x2+...+xi for each i=1,2,...,n. Use...
  8. D

    Sampling occurrence over time and repetition proof

    Hi, this isn't a homework problem, but pure curiosity. My friend is always on Facebook. I know this because I'm on often as well. However, as a joke, I posted a status saying she had no life. Another friend chimed in, with Now, I got to thinking. Is the a way, through statistics or some...
  9. F

    Probability of getting a 3 digit number without repetition.

    guys i encountered this problem and i'm kinda having a hard time answering it. can anybody help me if im on the right path and explain what to do next .here's the problem: given the #'s 0-9 what is the probability of getting a 3 digit number without repetition? how many of these numbers...
  10. S

    Number-of-ways sum.

    How many 4 digit numbers divisible by 5 can be formed with the digits 0,1,2,3,4,5,6,6 ? [Is there any general formula for nPr for the case where some of the objects are not distinct?]
  11. K

    Newton-Raphson Theorem Third Repetition Confirmation

    Hi, Can anyone confirm for me that the third Newton-Raphson repetition of f(x)=e^x+10x-3 at x=0 is approximately 0.18025?
  12. E

    Generating function for a sum without number repetition

    Hi Just wondering how to get a generating function to tell me the total number of combinations that add up to a particular number as follows. 1. 4 numbers added together that have a total of say 20. 2. The 4 numbers used must all be different and must be contained between say 1 and 30...
  13. C

    Permutations without Repetition

    How many different numbers can be formed by taking one, two, three, and four digits from the digits 1, 2, 7, 8, if repetition are not allowed ? Please Help (Crying)
  14. Y

    Probability of each combination with repetition

    Hi guys, It looks like trivial problem but I cannot solve it. I have M baskets and N balls. I can choose one of the baskets randomly and put a ball into the chosen basket. I'm just interested in combination. So in three baskets with 5 balls, (1) (1) (3) (1) (3) (1) (3) (1) (1)...
  15. T

    Integration by parts problem?!?!

    I know how to do integration by parts. ∫ u dv= uv-∫ v du as you may know for some functions like ∫ e^x cosx dx when you use integration by parts it repeats it's self. if you don't know what I mean, see the 3rd example on this page what I need to know...
  16. C


    Sorry, I do not know what to call this type of query. A class of nine kindergarten children is to be taken for a walk each afternoon. The teacher decides that they will 'walk in sets of three, and any pair of children will walk together on one day only. For how many days can this system be...
  17. S

    Python - Repetition (Iteration)

    Convert the following while loop into for loops and the for loops into while loops. *