The General Addition Rule | Probability | the virtual school
The General Addition Rule. This morning I
had a choice, I could either go to a cafe to eat breakfast or I could stay at home to
eat. I decided to go to a cafe. Because I went to the cafe I didn’t eat at home. The
two events are mutually exclusive, meaning that they couldn’t happen at the same time.
So, if I have a choice between two events, Event A or Event B, the probability of either
Event A or Event B happening is equal to the two separate probabilities added together. We can summarise this as P(A or B)=P(A)