Thread: Multiset

Would a question such as:
How many non-negative integer solutions are there to
x + y + z = 10?
be worked out as a multiset question?

I worked it out like this:

C(3+10-1,3) = C(12,3) = 220

Is this correct? If it's incorrect what is the proper way to solve these kinds of questions?

Originally Posted by Lupin

Would a question such as:
How many non-negative integer solutions are there to
x + y + z = 10?
be worked out as a multiset question?
I worked it out like this:

C(3+10-1,3) = C(12,9) = 220

Is this correct? If it's incorrect what is the proper way to solve these kinds of questions?

No. It should be

The multiset rule is: To make K selections from N different items is done in ways.

In this problem K=10 & N=3.

Thank you! I got it all figured out now.