Answer is k! * k^(n-k). You can select k number of balls in K! ways and then rest of (n-k) balls in k ways. This way you are ensuring that you have all k color balls and n number of balls in total.
- Kishen Das On Fri, Apr 30, 2010 at 6:04 AM, Ashish Mishra <[email protected]>wrote: > One of my friend ask me this n i am bad in P & C (will love if smone can > provide me a link to learn it though) > > nyways prob is: > there are infy color balls of k different color > you are allowed to pick n balls out of those infy(infinite) balls > > cond is : you must have all k color balls with u > obviously k<n > > Question is how many possibilities for selection you have ? > > Thanks > Ashish > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<algogeeks%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
