Notes And Formulas For Probability Class 9 Maths Download In Pdf

Chapter 15 Probability notes download in pdf which has explanation of probability tutorial, history of probability, probability theory, applications of probability, probability basics, theory of probability, probability ppt, application of probability, ppt on probability, probability concepts, what is probability, concept of probability, learn probability, meaning of probability, uses of probability, probability meaning, definition of probability, types of probability, define probability, probab

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

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

Please send your queries to ncerthelp@gmail.com you can aslo visit our facebook page to get quick help. Link of our facebook page is given in sidebar

- Chapter 1 NUMBER SYSTEMS
- Chapter 2 POLYNOMIALS
- Chapter 3 COORDINATE GEOMETRY
- Chapter 5 INTRODUCTION TO EUCLID’S GEOMETRY
- Chapter 6 LINES AND ANGLES
- Chapter 7 TRIANGLES
- Chapter 12 HERON’S FORMULA
- Chapter 4 Equations In Two Variables
- Chapter 8 Quadrilaterals
- Chapter 9 Areas of Parallelograms and Triangles
- Chapter 10 Circles
- Chapter 13 Volume and Surface Area
- chapter 14 Statistics
- Chapter 15 Probability
- Chapter 11: Constructions

- NCERT Solutions for Class 9 Science Maths Hindi English Math
- NCERT Solutions for Class 10 Maths Science English Hindi SST
- Class 11 Maths Ncert Solutions Biology Chemistry English Physics
- Class 12 Maths Ncert Solutions Chemistry Biology Physics pdf

- Class 1 Model Test Papers Download in pdf
- Class 5 Model Test Papers Download in pdf
- Class 6 Model Test Papers Download in pdf
- Class 7 Model Test Papers Download in pdf
- Class 8 Model Test Papers Download in pdf
- Class 9 Model Test Papers Download in pdf
- Class 10 Model Test Papers Download in pdf
- Class 11 Model Test Papers Download in pdf
- Class 12 Model Test Papers Download in pdf

Copyright @ ncerthelp.com A free educational website for CBSE, ICSE and UP board.