Class 9 Maths Probability – Get here the Notes for Class 9 Probability. Candidates who are ambitious to qualify the Class 9 with good score can check this article for Notes. This is possible only when you have the best CBSE Class 9 Maths study material and a smart preparation plan. To assist you with that, we are here with notes. Hope these notes will helps you understand the important topics and remember the key points for exam point of view. Below we provided the Notes of Class 9 Maths for topic Probability.

**Class:**9th**Subject:**Maths**Topic:**Probability**Resource:**Notes

## CBSE Notes Class 9 Maths Probability

Candidates who are pursuing in Class 9 are advised to revise the notes from this post. With the help of Notes, candidates can plan their Strategy for particular weaker section of the subject and study hard. So, go ahead and check the Important Notes for Class 9 Maths Probability from this article.

**MEANING OF PROBABILITY**

**In everyday life, we come across statements such as :**

1. It will probably rain today.

2. I doubt that he will pass the test.

3. Most probably, Kavita will stand first in the annual examination.

4. Chances are high that the prices of diesel will go Up.

5. There is a 50-50 chance of India winning a toss in today’s match.

The words ‘probably’, ‘doubt’, ‘most probably’, ‘chances’, etc. used in the statements above involve an element of uncertainty. For example, in (1), ‘probably rain’ will mean it may rain or may not rain today. We are predicting rain today based on our past experience when it rained under similar conditions. Similar predictions are

also made in other cases listed in (2) to (5).

The uncertainty of ‘probably’ etc. can be measured numerically be means of `probability’ in many cases.

**SOME IMPORTANT OBJECTS**

**(i) Coin :** We know that a coin has two faces : They are called Head and Tail.

**(ii) Die : (Dice) :** Die is a solid in the form of a cube, having six faces.

Each face has some marking of dots as shown above.

One face has one dot, second face two dots, third face has three dots and … so on. We take them as 1, 2, 3, 4, 5, 6. Plural of die is dice.

**(iii) Cards :** A pack of cards has 52 cards out of which 26 are red cards and 26 are black cards.

(a) 26 red cards contain 13 cards of **diamond **(♦) and 13 cards of **heart** (♥).

(b) 26 black cards contain 13 cards **spade** (♠) and 13 cards of **club** (♣)

(c) 13 cards are 1, 2, 3, …, 10,** Jack, Queen** and **King.**

(d) Card having 1 is also called an **ace.**

**PROBABILITY — AN EXPERIMENTAL (EMPIRICAL) APPROACH.**

A trial is an action which results in one or several outcomes. An event for an experiment is the collection of some outcomes of the experiment.

Let n be the total number of trials. The empirical probability P(E) of an event E happening, is given by

Number of trials in which the event happened

**Note :** The empirical probability depends on the number of trials.

**SOME BASIC TERMS AND CONCEPTS:**

**1. An Experiment :** An action or operation resulting in two or more outcomes is called an experiment

EX. (i) Tossing of a coin is an experiment.

There are two possible outcomes head or tail

(ii) Drawing a card from a pack of 52 cards is an experiment There are 52 possible outcomes.

**2. Sample space :** The set of all possible outcomes of an experiment is called the sample space, denoted by S. An element of S is called a sample point.

Ex. (i) In the experiment of tossing of a coin, the sample space has two points corresponding to head (H) and Tail (T) i.e S {H,T}.

Ex. (ii) When we throw a die then any one of the numbers 1, 2, 3, 4, 5 and 6 will come up. So the sample space, S = {1, 2, 3, 4, 5, 6}

**3. Event:** Any subset of sample space is an event.

Ex. (i) If the experiment is done throwing a die which has faces numbered 1 to 6, then S= {1,2,3,4, 5,6},A= {1,3,5},B {2, 4, 6}, the null set Φ and S itself are some events with respect to S.The null set Φ is called the impossible event or null event.

(ii) Getting 7 when a die is thrown is called a null event.

The entire sample space is called the certain event.

**Some Notes :**

(a) The probability of an event lies between 0 and 1, i.e., It can be any fraction from 0 to 1.

(b) The sum of the probabilities of all the possible outcomes of a trial is 1.

(c) Probability of the occurence of an event + Probability of the non-occurrence of that event = 1.

### Class 9 Key Points, Important Questions & Practice Papers

Hope these notes helped you in your schools exam preparation. Candidates can also check out the Key Points, Important Questions & Practice Papers for various Subjects for Class 9 in both Hindi and English language form the link below.

Class 9 Maths | कक्षा 9 गणित |

Class 9 Science | कक्षा 9 सामाजिक विज्ञान |

Class 9 English | |

Class 9 Social Science |

### Class 9 NCERT Solutions

Candidates who are studying in Class 9 can also check Class 9 NCERT Solutions from here. This will help the candidates to know the solutions for all subjects covered in Class 9th. Candidates can click on the subject wise link to get the same. Class 9 Chapter-wise, detailed solutions to the questions of the NCERT textbooks are provided with the objective of helping students compare their answers with the sample answers.

### Class 9 Mock Test / Practice

Mock test are the practice test or you can say the blue print of the main exam. Before appearing in the main examination, candidates must try mock test as it helps the students learn from their mistakes. With the help of Class 9 Mock Test / Practice, candidates can also get an idea about the pattern and marking scheme of that examination. For the sake of the candidates we are providing Class 9 Mock Test / Practice links below.

### Class 9 Exemplar Questions

Exemplar Questions Class 9 is a very important resource for students preparing for the Examination. Here we have provided Exemplar Problems Solutions along with NCERT Exemplar Problems Class 9. Question from very important topics is covered by Exemplar Questions for Class 9.

CBSE Class 9 Maths Notes Science Notes Social Science Notes English Notes