Actually those words have very little relation to the usage of addition or multiplication.

The most widely used set of axioms for probability contains three axioms. One theorems we can prove is:

I chose that theorem to illustrate the ‘mixed’ nature of your question.

Let’s examine those two words.

means the probability of both events occurring together. Both happen.

On the other hand, means the probability of at least one of the events occurs. One or both happen.

Finding what , can be easy or difficult.

If events arethen .independent

But if they arethen things get more complicated.dependent

So you need to stay tuned in the course for what is to come.