Probability Concepts: Total, Addition, Multiplication and Bayes

Hey guys,

This seems to be the one of the hardest topics that I can’t handle after all this time.

I cannot fully understand what formula to use or when to use or how to use. I can at least grasp the logic behind it, but I’m stuck at determining how to find the probability that is needed. I sometimes add when I should multiply or multiply when I should be dividing and so on and so on.

I might have to resort towards memorization but even then, it might not be much of a help when I don’t know which formula or method to use.

Some help is appreciated.


Edit: I understand the notions, such as P(A|B) is probability of A given B etc etc but I have no idea how to use or find when given the question in an essay format.

Can you provide us with example questions you’re struggling with? Then we can help you understand how to calculate the correct probabilities.