Take the 2-minute tour ×  If anyone has a free, online source to
contribute for a certain topic/topics, please share! I'm not
really looking for an intense theoretical grasp of these topics,
just an intuitive understanding of how they work and how they
can be applied to practical problems.  Counting stuff    1. The
pigeonhole principle.   2. Permutations/combinations.   3.
Binomial coefficients.   4. Generalized
permutations/combinations (repetition, indistinguishable
objects, etc.).  Probability stuff    1. Probability theory
(conditional probability, independence, Bernoulli
trials/distributions, random variables).   2. Baye's theorem.
3. Expected value and variance.  Anything to contribute would be
extremely helpful. Even posts on the StackExchange website can
help tremendously if they're relevant.  Thank you all for the
help :)  share|improve this question add comment  1 Answer  up
vote 1 down vote accepted  You could find some interesting
materials in this site:   The following notes are rather
interest