Probability Formula Class 9
Probability of an event can be calculated by applying the probability formula. It is determined by simply dividing the favorable number of outcomes by the total number of possible outcomes. Students can learn to determine the probabilities of various events by memorizing the probability formula class 9. This article provides a list of important probability formulas along with some useful tips to help students comprehend the idea of probability.
List of Probability Formula Class 9
Students can refer to the important concepts and formulas explained below in the list of Probability Formula Class 9:
 Event: An event for an experiment is the collection of some outcomes of the experiment.
 The empirical (or experimental) probability P(E) of an event E is given by
P(E) = Number of trials in which E has happened/Total number of trials
 The Probability of an event lies between 0 and 1 (0 and 1 inclusive)
Applications of Probability Formula Class 9
Probability formulas are applied extensively in various sciences like medical sciences, physical sciences, weather forecasting, commerce, etc. Here are a few examples of
applications of probability formulas class 9:

Probability formulas are used by meteorologists in determining the probability of earthquakes in an area. This probability is calculated based on the occurrence of earthquakes in that area so far.

Based on the number of times a team has won a tournament in the past the probability of the team winning the next tournament can be calculated by applying Probability formulas class 9.
Probability Formula Class 9 Examples
Example 1: Two identical coins are tossed 100 times and we get the frequency distribution as 
Two Heads: 30 times
Two Tails: 40 times
One Head: 30 times
Find the probability of each of the above three possible outcomes?
Solution :
Probability of Getting two heads = E1 = 30/100 = 0.3
Probability of Getting two tails = E2 = 40/100 = 0.4
Probability of Getting one head = E3 = 30/100 = 0.3
Also, we can see sum of E1 + E2 + E3 = 1
Example 2: In a survey done for 200 students, 90 students like to play football and 110 students like to play cricket. What is the probability of selecting a student who likes to play cricket and football?
Solution: Probability = Number of students who like cricket/Total students
= 110 /200
= 11/20 = 0.55
Tips to Memorize Probability Formula Class 9
Students can learn the probability formula class 9 by following the tips below:
 Writing down formulas is one of the most effective ways to retain them. Students will gain a better comprehension of the concepts and formulas if they practice this on a daily basis.
 Students must go over all of the solved examples in their textbook and attempt to solve them on their own after they understand the logic behind the formulas. This will help them get familiarized with range of formula applications. They should then practice the exercise questions to have enough problemsolving experience.
 Students can download formula images to use them as wallpaper on their computers and mobile devices. This will provide them with a quick revision every time they use these devices.
Students can download the printable Maths Formulas Class 9 sheet from below.
FAQs on Probability Formula Class 9
What are the Important Formulas Covered Under Probability Formula Class 9?
The important formulas in probability formula class 9 are given below:
 Experimental Probability Formula: The Trial counts in which the event(E) has occurred / Sum total of trials
 The Probability of an event varies from 0 and 1.
What are the Basic Concepts Used in Probability Formula Class 9?
The basic concepts used in probability formula class 9 are based on determining empirical probability and defining its limiting value. Students can go through these basic formulas in this article and also the tips which will help them to remember these formulas effectively.
What are the Important Formulas Covering Probability Formula Class 9?
The important formulas in probability formula class 9 cover the experimental probability. Students can go through the examples based on the same in this article to understand the formula. Students must make sure they are thorough with the concepts of trial, events and outcomes that will make the learning process smooth.
How many Formulas are There in Probability Formula Class 9?
There are two basic formulas in probability formula class 9. The first one is regarding how to calculate the empirical or experimental probability by dividing the number of trials in which the event has happened by the total number of trials. The second one states that the probability value lies between 0 and 1.
How to Memorize Probability Formula Class 9?
Some of the ways in which students can memorize the probability formula class 9 are mentioned below:
 One of the most effective ways to remember formulas is to write them down along with explanations. If students practice this on a daily basis, they will get a deeper understanding of the concepts and formulas.
 After understanding the theory behind the formulas, students must go over all of the solved examples in their textbook and attempt to solve them on their own. As a result, they will be exposed to a wide range of formula applications. They should then practice the exercise questions until they are confident in their ability to solve problems.
 Students can also use formula images as wallpaper on their desktops and mobile devices for a quick revision.
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