Probability

What is Probability Class 10 Maths: Definition and Key Concepts

By ConceptScroll Team · Published on 19 June 2026 · 3 min read

What is probability class 10 maths? Probability measures the chance of an event happening, expressed as a number between 0 and 1. This chapter in NCERT Class 10 Maths introduces basic concepts and formulas to calculate probabilities in different scenarios.

Understanding Probability: Definition and Basics

Probability is a branch of mathematics that deals with the likelihood of an event occurring. In Class 10 NCERT Maths, probability is defined as the ratio of favorable outcomes to the total number of possible outcomes, provided all outcomes are equally likely.

The formula for probability is:

$$ P(E) = \frac{\text{Number of favorable outcomes}}{\text{Total number of possible outcomes}} $$

Where $P(E)$ is the probability of event $E$. The value of probability always lies between 0 and 1, inclusive.

  • If $P(E) = 0$, the event is impossible.
  • If $P(E) = 1$, the event is certain.

This fundamental concept helps students solve various problems involving chance and uncertainty.

Types of Events in Probability

In Class 10 Probability, understanding different types of events is crucial:

  • Certain Event: An event that will definitely happen. Example: Getting a number between 1 and 6 when rolling a dice.
  • Impossible Event: An event that cannot happen. Example: Getting a 7 on a standard dice.
  • Favorable Event: Outcomes that satisfy the event condition.
  • Unfavorable Event: Outcomes that do not satisfy the event.

Knowing these types helps in correctly identifying favorable outcomes and calculating probability accurately.

Want to test yourself on Probability? Try our free quiz →

Worked Example: Calculating Probability of an Event

Let's solve a typical Class 10 NCERT probability problem:

Example: A bag contains 5 red balls and 3 green balls. One ball is drawn at random. Find the probability that the ball drawn is red.

Solution:

  • Total balls = 5 + 3 = 8
  • Favorable outcomes (red balls) = 5

Using the formula:

$$ P(\text{red ball}) = \frac{5}{8} $$

So, the probability of drawing a red ball is $\frac{5}{8}$.

This example shows how to apply the probability formula to real-life problems.

Important Formulas and Tips for Class 10 Probability

Here are key formulas and tips to remember for your Class 10 Probability chapter:

  • Basic Probability Formula:

$$ P(E) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} $$

  • Probability of Not E:

$$ P(\text{not } E) = 1 - P(E) $$

  • Always verify that all outcomes are equally likely before applying formulas.
  • Practice solving NCERT exercises to strengthen concepts.
  • Use diagrams or lists to count outcomes clearly.

Following these tips will boost your confidence and exam performance.

How Probability is Important for Class 10 Exams

Probability is an important chapter in the Class 10 NCERT Maths syllabus. It is frequently tested in CBSE board exams through:

  • Direct questions on definitions and formulas
  • Problems requiring calculation of probabilities in real-life contexts
  • Application-based questions involving dice, coins, and cards

Understanding probability helps develop logical thinking and decision-making skills. Regular practice of NCERT examples and exercises ensures you can solve all types of probability questions with ease.

Frequently asked questions

What is the probability of an impossible event?

The probability of an impossible event is 0 because it cannot happen.

How do you calculate probability in Class 10 Maths?

Probability is calculated by dividing favorable outcomes by total possible outcomes.

Can probability be greater than 1?

No, probability values always lie between 0 and 1 inclusive.

What is the difference between probability and odds?

Probability is the chance of an event happening; odds compare favorable to unfavorable outcomes.

Why is probability important for Class 10 exams?

Probability is a key chapter in NCERT Maths and often appears in CBSE exams.

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