 ### What is Probability? Experiment, Outcome and Event - Examples - Class 8

Probability is that part of mathematics that deals with this area of uncertainty. In our daily life we come across many situations where we deal with decision making.

� When we get up in the morning at we decide that we should go to school today or not.
� Which dress we should wear in the party?
� What should we play?
� Which subject we should study first?

And many more.

You might have seen that before a hockey match starts, captains of the two teams go out to toss a coin to decide which team will play first.

What are the chances of winning toss by team A?

The chances of winning toss by team are 50%. As there are 2 teams team A and team B and 2 results i.e. head and tail. If team A wins Team B will lose and vice versa. So both the teams have 50 � 50 chance of winning toss.

So the probability is a number assigned to an event that tells us the chances of occurring of that event.

To check the probability we have experiment.

Experiment is a situation involving chance or probability that leads to an outcome.

Like here On throwing a coin getting head is an outcome. An outcome is a result of a single trial of an experiment.

Head and Tail are the two outcomes of this experiment.

On throwing dice getting 6 is an outcome.

Anu & Manu are playing ludo. This is an experiment. On rolling a dice and getting a number say 4 is an outcome. Each outcome or collection of outcomes makes an event. Here getting each outcome 1, 2, 3, 4, 5 and 6 is an event. There is one more term related to probability i.e., random experiment.

A random experiment is that in which outcomes may differ each time when the experiment is performed.

Now Anu rolled the dice.

What is the probability of getting 5? On Rolling dice the probability of getting 5 is 1 upon 6.

The outcomes are 1, 2, 3, 4, 5, 6. Thus, there are six equally likely outcomes. Thus the probability of getting 5 is 1 upon 6. So to find the probability of an event happening we need to divide the number of ways it can happen by the total number of outcomes.

For example, there are 7 marbles in a bag, 4 are red and 3 are blue. What is the probability that a blue marble will be picked?

Number of ways it can happen: 3 (there are 3 blues)

Total number of outcomes = 7 (there are 7 marbles in total)

So the probability is 3/7.