balls be distributed

In how many ways can 20 identical balls be distributed among 9 children?

i want to make it clear:

*all 20 balls may not be distributed
*each of them may not get a ball

7 Answers

62
Lokesh Verma ·

29C9

62
Lokesh Verma ·

The reason is simple there are 20 balls and putting 9 dividers will divide the balls in 10 parts.. 1 part will not be distributed.. the other 9 will be given in order to the 9 children

13
Двҥїяuρ now in medical c ·

but i think it should be 28c8

62
Lokesh Verma ·

*all 20 balls may not be distributed
*each of them may not get a ball

If this second condition was not there..

that each ball may not be distributed.. u wud be right..

but we have to keep one part with ourselves :)

13
Двҥїяuρ now in medical c ·

i got it

Thank u.....

13
Двҥїяuρ now in medical c ·

I think it should be..........(29C9 - 1)

we should not take the case where no balls were distributed among the children.

62
Lokesh Verma ·

hmm.. may be .. but then these small things depend on the writer of the question (he needs to be a bit more specific at times :)

but i guess the essense of solving these problems is very imporatant..

in IIT u wiill never get vague questions ... so :)

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