here is how i got combinations with 4 variables and third expansion
so there are 40 combinations
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
To be honest I don’t really follow your question.
I think you mean if there are ten symbols, ABCDEFGHIJ, how many strings of length ten can be formed using any or all of the ten.
For example: are two possible strings.
In that example there are possible strings.
In general, if you have different symbols the number of possible strings of length , using any or all of the symbols, is
If you mean something else, please try to make it clearer.