Impossible event is denoted by φ , while Sure Event is denoted by S .
E . g . in rolling a die , impossible event is that number is more than 6 & Sure event is the event of getting number less than or equal to 6 .
Simple Event has only one sample point of a sample space . E . g . in rolling a die , Simple event could be the event of getting 4 .
Compound Event has more than one sample points of a sample space .
E . g . in rolling a die , Simple event could be the event of getting even number
Algebra of Events o
Complementary Event o Event ‘ A or B ’ o Event ‘ A and B ’ o
Event ‘ A but not B
Complementary Event
Complementary event to A = ‘ not A ’
Example : If event A = Event of getting odd number in throw of a die , that is { 1 , 3 , 5 }
Complementary event to A = Event of getting even number in throw of a die , that is { 2 , 4 , 6 }
Or A ’ = S- A ( where S is the Sample Space )