Class 12 Mathematics Chapter 13 Probability – Revision Notes

Quick revision notes for Class 12 Maths Chapter 13 (Probability). These Class 12 Mathematics Chapter 13 notes are ideal for quick revision just before exams.

Key Formulas

• Conditional: P(A|B)=P(A∩B)/P(B).
• Multiplication: P(A∩B)=P(A)P(B|A).
• Independence: P(A∩B)=P(A)P(B).

Bayes & Distributions

• Total probability: P(A)=ΣP(E_i)P(A|E_i).
• Bayes theorem: P(E_i|A)=[P(E_i)P(A|E_i)]/ΣP(E_j)P(A|E_j).
• Binomial: P(X=r)=ⁿC_rp^rq^n−r.
• Mean=Σx_ip_i; Variance=E(X²)−[E(X)]².

One-Line Summary

Probability in Class 12 builds on conditional probability and independence to Bayes theorem for reversing conditioning, and to random variables/binomial distributions for modeling repeated trials.

Written by Satish

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