Experiment:Any activity
which results in outcomes is called an experiment.
E.g.
tossing a coin,rolling a die.
Event: An outcome of a
random experiment is called an event.
FavorableEvent: The favorableoutcome is called favorable event.
e.g.Getting
a head, getting even number on die.
Probability
of an event:
*
If there are n
elementary events associated with a random experiment and m of them are favorable
to an event , then the probability of happening or occurrence
of event A is denoted by and is defined as the ratio .
Thus,
Elementary
event:
An event having only one outcome is
called elementary event.
For e.g .getting a head
Complimentary
event:
For an event , the event
“not” is called complimentary event.
It is denoted by .
e.g.for event “getting even numbers”, the complimentary
event is “ getting odd
numbers”
proof: If
total no. of outcomes
total no. of favorable
outcome of
Total no.of
non favorable
Then
And
Sure
event:
The
event which is sure or which has probability is called sure event.
Impossible
event:
The
event which is not possible or which has probability is called impossible event.
Range
of probability
As
Clearly,
.
Sum
of probabilities of all elementary:
Sum
of probabilities of all elementary events is .