Combnatorics problem

CAn u give some material related to combinatorics beacause I am getting a lot of doubts in it.

is this heplful??

It is.Along with it can yo give some combinatorics formula which are frequently used for competitive programming

this is best for competitive Programming

I hope I’ve cleared your doubt. I ask you to please rate your experience here
Your feedback is very important. It helps us improve our platform and hence provide you
the learning experience you deserve.

On the off chance, you still have some questions or not find the answers satisfactory, you may reopen
the doubt.