Class 11 Maths Chapter 6 Permutations and Combinations – Revision Notes

Quick revision notes for Class 11 Maths Chapter 6 (Permutations and Combinations). These Class 11 Maths Chapter 6 notes are ideal for quick revision just before exams.

Fundamental Counting Principle

• m ways × n ways = m×n ways (combined events).

Factorial

• n! = n×(n−1)×…×1; 0! = 1.

Permutations (order matters)

• ⁿP_r = n!/(n−r)!.

Combinations (order doesn’t matter)

• ⁿC_r = n!/[r!(n−r)!].

Relationship

• ⁿP_r = ⁿC_r × r!.

One-Line Summary

Permutations count ordered arrangements while combinations count unordered selections, related by ⁿP_r = ⁿC_r×r!, both built on the factorial and fundamental counting principle.

Written by Satish

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