NCERT Solutions Class 11 Maths Chapter 6 Permutations and Combinations Exercise 6.2

The NCERT Solutions for Class 11 Maths Chapter 6 Permutations and Combinations Exercise 6.2 cover every question of the second exercise, according to the latest 2026-27 CBSE syllabus. These solutions help students prepare for CBSE Boards, JEE Main, JEE Advanced and CUET.

Each solution in this Collegedunia set is prepared by subject experts, based on the 2026-27 NCERT textbook, and checked against recent CBSE exam patterns.

Exercise 6.2 introduces factorial notation, the key tool for writing and simplifying permutation formulas. The exercise has 5 questions built around these skills:

• Evaluating factorials such as 8! and simple factorial differences.
• Simplifying expressions like n! / (n − r)! by cancelling.
• Solving small equations that involve factorials.

Topics Covered in Exercise 6.2

This exercise builds the factorial idea that every permutation formula depends on. The factorial of a natural number n, written n!, is the product of all natural numbers from 1 up to n. Exercise 6.2 keeps the focus on evaluating, simplifying and comparing factorial expressions before permutations are introduced formally.

• Factorial value: computing n! = n × (n − 1) × ... × 2 × 1.
• Zero factorial: the special rule that 0! = 1.
• Factorial identity: writing n! = n × (n − 1)! to cancel terms.
• Simplifying ratios: reducing n! / (n − r)! without full multiplication.
• Solving for x or n: forming a small equation and comparing factorials.

Important: to simplify a factorial ratio, expand only the larger factorial down to the smaller one, then cancel. This avoids multiplying out full factorials.

Question-wise Breakdown of Exercise 6.2

The NCERT Solutions for Class 11 Maths Chapter 6 Permutations and Combinations Exercise 6.2 solve all 5 questions in order. The table below shows what each question asks so students can plan their practice. Full step-by-step answers are inside the PDF above.

The questions are short and build directly toward the permutation formula introduced in Exercise 6.3.

Key Formulas and Definitions for Exercise 6.2

Exercise 6.2 depends entirely on the definition of factorial and a few identities. Students should memorise these before attempting permutations.

Tip: factorials grow very fast, so never compute 8! fully when a 6! or 7! cancels. Expand only as far as needed and cancel early.

Common Mistakes in Exercise 6.2

Students lose easy marks in Exercise 6.2 through slips with factorial rules. The list below covers the errors that show up most often in class tests on the NCERT Solutions for Class 11 Maths Chapter 6 Permutations and Combinations Exercise 6.2.

• Assuming (a + b)! equals a! + b!. Factorials do not split over addition, so 3! + 4! is not 7!.
• Forgetting that 0! = 1 and writing it as 0.
• Multiplying out full factorials instead of cancelling, which wastes time and invites arithmetic errors.
• In the equation question, forgetting to bring both fractions to a common factorial denominator before comparing.

Practice Questions for Exercise 6.2

After reading the solutions, students should test themselves on the same question types. The card below opens a set of solved practice questions with step-by-step answers for Exercise 6.2.

Other Exercises of Chapter 6 Permutations and Combinations

Chapter 6 Permutations and Combinations has four exercises plus a Miscellaneous Exercise. Use the table to move to another exercise once Exercise 6.2 is done.

More Class 11 Maths Permutations and Combinations Resources

Pair the solutions with the notes and the NCERT book PDF for full chapter revision. All three resources for Chapter 6 Permutations and Combinations are linked below.

NCERT Solutions for Other Class 11 Maths Chapters

Students can move to the first exercise of any other Class 11 Maths chapter using the cross-sell table below.

FAQs on NCERT Solutions for Class 11 Maths Chapter 6 Permutations and Combinations Exercise 6.2