Class 11 Maths Chapter 14 Probability – Revision Notes

Quick revision notes for Class 11 Maths Chapter 14 (Probability). These Class 11 Maths Chapter 14 notes are ideal for quick revision just before exams.

Key Terms

• Random experiment; Sample space (S); Event = subset of S.

Event Types

• Impossible (∅): P=0. Sure (S): P=1.
• Complement: P(A’)=1−P(A).
• Mutually exclusive: no overlap.

Probability Formula

• P(A) = n(A)/n(S); 0≤P(A)≤1.

Addition Rule

• P(A∪B) = P(A)+P(B)−P(A∩B).
• Mutually exclusive: P(A∪B)=P(A)+P(B).

One-Line Summary

Theoretical probability is calculated as favourable outcomes over total outcomes in the sample space, with the addition rule handling combined events by subtracting any overlap to avoid double-counting.

Written by Satish

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