DEFINITIONS OF PROBABILITY

THE NAMING CEREMONY

D e f i n i t i o n 1:- 

Probability is the numerical measure of likelihood that a certain outcome of a random experiment will occur. 

D e f i n i t i o n 2:- 

Probability is a concept which numerically measures the degree of uncertainity and therefore of the certainity of the occurance of events. 

To know more about uncertainity factor or probability lets be friends with the following terms:-

RANDOM  EXPERIMENT

Let us take an example to understand this concept technically:-

A bag contains 4 green marbles, 5 red marbles, and 3 black marbles. If we draw just one marble out of the 12 marbles without seeing their colour and suppose we need a red marble then the possibilities of getting a green or a black marble ruled out. So, the result of the experiment which we have made cannot be predicted beforehand. This experiment is of a different nature in comparison to the experiments carried out in physical sciences.

Here, an experiment repeated under same conditions may not give the same result. Such experiments are called “Random Experiments”

That is ‘An Experiment which has more than one possible outcome is called a ‘RANDOM EXPERIMENT’

In our study of the theory of probability, we shall deal with experiments underlying ‘Probabilistic phenomena’

Some of the examples of Random Experiment are:-

• Tossing a coin
  
• Throwing a dice
  
• Selecting a card from a pack of 52 playing cards etc.
  

In all the cases there are number of possible results which can occur but there is an uncertainty as to which one of them will actually occur.