On this page, you will find Probability Class 9 Notes Maths Chapter 15 Pdf free download. CBSE NCERT Class 9 Maths Notes Chapter 15 Probability will seemingly help them to revise the important concepts in less time.

## CBSE Class 9 Maths Chapter 15 Notes Probability

### Probability Class 9 Notes Understanding the Lesson

1. Experiment: A procedure which produces some well-defined possible outcomes.

2. Random experiment: An experiment which when performed produces one of the several possible outcomes called a random experiment.

3. Trial: When we perform an experiment it is called a trial of the experiment.

4. Event: The set of outcomes of an experiment to which probability is assigned.

5. The empirical (or experimental) probability P(E) of an event E is given by
$$\mathrm{P}(\mathrm{E})=\frac{\text { Number of trials in which } \mathrm{E} \text { has happened }}{\text { Total number of trials }}$$
So, Probability of not happening an event $$\mathrm{P}(\overline{\mathrm{E}})$$= 1 – P(E)

6. The probability of an event lies between 0 and 1 (0 and 1 are included).

7. Impossible event: An event which never happens.

8. Certain event : An event which definitely happens.