In how many different ways can six identical coins be distributed among Al, Bo, and Carl so that each gets at least $$1$$ oin? 
Overseas Competition->Knowledge Point->Counting Modules->Permutations and Combinations->Combinations
The only possible distributions (Al, Bo, Carl) are these ten: $$(1,1,4)$$, $$(1,2,3)$$, $$(1,3,2)$$, $$(1,4,1)$$, $$(2,1,3)$$, $$(2,2,2)$$, $$(2,3,1)$$, $$(3,1,2)$$, $$(3,2,1)$$, and $$(4,1,1)$$. 