A sample space is called an Equiprobable space iff all the simple events are equally likely to occur:
→Probability of occurrence of the event , donated by , is defined by
where is the Sample Space.
→Probability of non-occurrence of
Algebra of Events:
(i) For any event ≤ ≤ .
(iii) , where is empty set.
(v) If are two events and , then ≤
(vi) If are any two events, then
(vii) If are mutually exclusive events, that is , then
(x) If are events, then:
(xi) For are mutually exclusive events
(xii) ( at least two of occur)
(xiii) ( Exactly two of occur)
(xiv) ( Exactly one of occur )
If three events are pairwise mutually exclusive, then they must be mutually exclusive, that is
If and are two events, then:
For mutually exclusive events that is , then and