Need help! - Terrible at hard probability & perm/comb

[Meggieski]

Hi All,

I just cannot seem to grasp these topics at higher levels. I can do the standard stuff but every time I see a harder question where arrangements are dependent on placement of items, repetition etc.. I just cannot figure it out.

Does anyone have any good sources that they could refer me to? I'd be most appreciative!

Thanks

[shailender.bisht]

have a look at this website:

Combinations and Permutations

and the practice all the question you can find.
I hope that after doing a lot of this stuff you will find it easier to start developing a sense of Prob questions.