The Mathematics of Maybe: Introduction to Probability

Chapter at a glance

Probability as a measure of how likely an event is: experimental and theoretical probability, sample spaces, events and tree diagrams.

What this chapter covers

• 7.1 What is Probability?
• 7.2 Measuring Probability Objectively
• 7.3 Elements of Probability: Sample Spaces and Events
• 7.4 Tree Diagrams

Key points

• 0 ≤ P(E) ≤ 1: 0 means impossible, 1 means certain.
• Experimental probability = number of times the event occurred ÷ total number of trials.
• Theoretical probability = favourable outcomes ÷ possible outcomes, when all outcomes are equally likely.
• A sample space lists all outcomes; an event is one or more outcomes; tree diagrams list and visualise outcomes.

Read the NCERT chapter

Read this chapter in the official NCERT textbook Ganita Manjari (2026-27 edition) for free on ncert.nic.in.

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