I am confused in how to interpret two alike combinatorial problems, because to me they both look the same. These are the problems:
- How many ways are there to put $24$ distinguishable flags on $18$ distinguishable flagpoles?
The answer to this problem is $\binom{18+24-1}{24}24!$, so first is to arrange the flags as if they were indistinguishable and the arrange them in order.
- How many ways are there to put 8 distinguishable balls into 10 distinguishable boxes?
The answer to this question is $10^8$.
If the first problem I consider it as distinguishable balls in distinguishable boxes, both problems should be the same, what's the catch then?
The order of the flags on each flagpole matters.
Once we have decided which objects go into which box, their order within the box does not matter.