If ⁿP₃ = ⁿP₄ = 1 : 5, then the value of n is :
**Permutations and Combinations**, Chapter 6 of the NCERT Maths textbook for Class 11th (CBSE 2024-2025), is a fascinating exploration of counting and arrangement techniques. This chapter introduces students to factorial notation, permutations, combinations, and their practical applications in problem-solving. It forms the backbone of advanced mathematical concepts like probability and statistics. The chapter is enriched with **MCQ questions** that challenge students to apply their knowledge and sharpen their analytical skills. These questions are excellent tools for self-assessment and exam preparation, ensuring a deep understanding of the topic. By mastering permutations and combinations, students develop critical thinking and logical reasoning, essential for excelling in academics and competitive exams. A strong grasp of this chapter opens doors to endless mathematical possibilities.
Share
Choice (a) is correct
Given, ⁿP₃ : ⁿP₄ = 1 : 5
⇒ ⁿP₃/ ⁿP₄ = 1/5 ⇒ (n!/(n -3)!)/ (n!/ (n – 4)!) = 1/5 ⇒ (n – 4)!/ (n -3)! = 1/5
⇒ (n – 4)! / (n – 3) (n – 4)! = 1/5 ⇒ 1 / n – 3 = 1/5
⇒ n – 3 = 5 ⇒ n = 8
This question related to Chapter 6 maths Class 11th NCERT. From the Chapter 6: Permutations and Combinations. Give answer according to your understanding.
For more please visit here:
https://www.tiwariacademy.com/ncert-solutions/class-11/maths/#chapter-6