Official Class 9 Mathematics Revision Material: CBSE Class 9 Mathematics Probability Notes Set 21
Review targeted revision notes for Class 9 Mathematics with the CBSE Class 9 Mathematics Probability Notes Set 21. Built according to official educational guidelines for the 2026-27 academic year, these downloadable summaries for Chapter 15 Probability support daily study and last-minute exam readiness.
Chapter-wise Concept Summaries: Chapter 15 Probability
Access the complete concept summary PDF for Chapter 15 Probability below. Regular review of these targeted notes builds familiarity with complex Class 9 Mathematics themes and helps secure higher marks in final school evaluations.
Basic Terms
An experiment is an activity with uncertain results, such as tossing a coin or throwing a die. Each result is an outcome and the set of all outcomes is the sample space. An event is a collection of outcomes. Outcomes are equally likely when none is favoured over another.
Definition of Probability
P(A) = number of outcomes favourable to A ÷ total number of equally likely outcomes. The value always lies from 0 to 1: 0 for an impossible event and 1 for a sure event.
Complement and Odds
P(not A) = 1 − P(A). If the odds in favour of an event are m : n, then P(event) = m/(m + n) and P(not event) = n/(m + n).
Standard Experiments
Two coins: 4 outcomes (HH, HT, TH, TT). Three coins: 8 outcomes. One die: 6 outcomes. Two dice: 36 outcomes. Pack of 52 cards: 26 red, 26 black, 4 suits of 13, 12 face cards (K, Q, J), 4 aces.
Experimental Probability
When an experiment is actually performed n times, the experimental probability of an event = number of times it occurred ÷ n.
Solved Example
Two dice are thrown together. Find the probability of a total of 9.
Favourable: (3,6), (4,5), (5,4), (6,3) = 4 out of 36, so P = 1/9.
Solved Example 2
A card is drawn from a pack of 52. Find the probability that it is neither a heart nor a king.
Hearts or kings: 13 + 4 − 1 = 16, so neither = 36 and P = 36/52 = 9/13.
Free study material for Mathematics
Chapter 15 Probability Concepts and Summary for Class 9 Mathematics
About Chapter 15 Probability Revision Notes
Review targeted chapter notes for Class 9 Mathematics Chapter 15 Probability. Built according to official CBSE guidelines, these summaries highlight high-yield topics frequently tested in school evaluations.
How to Use These Revision Notes
Cross-reference your comprehension with comprehensive NCERT solutions for Class 9 to ensure absolute clarity across all sub-topics in this chapter.
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FAQs
You can download the teacher prepared revision notes for CBSE Class 9 Mathematics Probability Notes Set 21 from StudiesToday.com. These notes are designed as per 2026-27 academic session to help Class 9 students get the best study material for Mathematics.
Yes, our CBSE Class 9 Mathematics Probability Notes Set 21 include 50% competency-based questions with focus on core logic, keyword definitions, and the practical application of Mathematics principles which is important for getting more marks in 2026 CBSE exams.
Yes, our CBSE Class 9 Mathematics Probability Notes Set 21 provide a detailed, topic wise breakdown of the chapter. Fundamental definitions, complex numerical formulas and all topics of CBSE syllabus in Class 9 is covered.
These notes for Mathematics are organized into bullet points and easy-to-read charts. By using CBSE Class 9 Mathematics Probability Notes Set 21, Class 9 students fast revise formulas, key definitions before the exams.
No, all study resources on StudiesToday, including CBSE Class 9 Mathematics Probability Notes Set 21, are available for immediate free download. Class 9 Mathematics study material is available in PDF and can be downloaded on mobile.