## Rules of Probability

__: The slide shown between 2:42 and 4:14 has the words: "If A and B are independent/disjoint" this should simply say "If A and B are independent."__

**Correction to the video**A and B are independent means that the probability of one occurring doesn't affect the other occurring.

A and B are disjoint means that they don't happen at the same time.

So we wouldn't want to look at the probability that they both happen if they can't happen at the same time.

For more help, check out this reference.