hello...
I'm having a bit of problem with one simple task
First sorry if I put this thread in wrong place
I know how to calculate number of combinations (without repetition)
and that's ok
but now I have big problem
I have to calculate number of combinations with repetitions
so i tried like this
when i have 2 variables A and B with second expansion i have :
so it's four combinations
for third expansion i have :
so there is 8 combinations .... and at first i think formula should be
or in my case now
meaning
but as I get to problem with 4 variables and need to do third expansion by that formula I need 64 combinations... I wrote all of them and I got 40... now I'm confused very much because in next task I have problem with 10 variables and third expansion ... and there is no way that i can wrote them all to find pattern ....
can anyone please help me with this
I also find some formulas for similar things but none of them can be any use to me in this problem