Hi,
I'm trying to improve myself in solving problems about probabilities and mathematical
expectation, but I find most of problems hard to me especially those problems where
I need to find the expected value, because I feel that every problem needs a way
to think about that is different from the other problems, and trying to apply
the formal definition of the expected value is always useless.
So, could you please provide me with a way to improve myself or some stuff to study from ?