Tricki

## Revision of To compute that exactly k of n events occur, use generalized inclusion-exclusion from Tue, 12/05/2009 - 21:55

### Quick description

Suppose that , , ..., are events and you want to calculate the probability that exactly of these events occur. That is, you would like to compute the probability of the set of samples that belong to exactly of these sets. One can use the following generalized inclusion-exclusion formula to accomplish this:

This formula is computationally useful if it is simple to compute the probabilities . For more information on this formula see the article on the simple inclusion-exclusion principle.

### Prerequisites

Elementary probability.