Definition:Two events A and B are mutually exclusive,or disjoint,if AnB=0. This means events A and B cannot happen together.If A happens, it excludes B from happening,and vice-versa Note:Does this mean that A and B are independent? No,quite the opposite.A EXCLUDES B from happening,so B depends strongly on whether or not A happens. Definition:Any number of events 4.4..4 are mutually exclusive if every pair of the events is mutually exclusive:ie. AinA=0 for all i.j withi j. Definition:A partition of the sample space is a collection of mutually exclusive events whose union is That is,sets B,B....B form a partition of if BinBj 0 for all i,j withij, and B:B UB2U...UBk Q. =1 Examples: 8/258 / 25 Definition: Two events A and B are mutually exclusive, or disjoint, if This means events A and B cannot happen together. If A happens, it excludes B from happening, and vice-versa. Note: Does this mean that A and B are independent? No, quite the opposite. A EXCLUDES B from happening, so B depends strongly on whether or not A happens. Definition: Any number of events A A An , , , 1 2  are mutually exclusive if every pair of the events is mutually exclusive: ie. Definition: A partition of the sample space Ω is a collection of mutually exclusive events whose union is Ω