NCERT Solutions for Class 11 Maths Chapter 7 - Permutations and Combinations

Under this chapter, the definition of Permutation and Combination is given where a permutation means arranging several objects in a specific order taken one at a time. And, the combination means a collection of the objects, irrespective of the order.

In these NCERT Solutions for class 11th Maths chapter, the Fundamental principle of counting, permutations, factorial n. (n!), combinations, derivations of formulae, their connections, and simple applications are supposed to be taught. The CBSE Board has given four exercises in total for the students' practice, plus a miscellaneous exercise expanding the whole chapter. Following are the topics discussed in this chapter:

• Fundamental Principle of Counting

The two fundamental theorems of counting have been discussed in this section of the topic.

• Permutations

The sub-topics taught under this are Permutations in case all the objects/elements are distinct, Factorial notion, Deriving the formula for nPr, and Permutations in case all the objects are not different.

• Combinations

All the different manners/ways by which elements/objects of a particular set can be picked without any substitutes and form subsets are defined as Permutation and Combination. Here, the subset selection is called a permutation, acknowledging the factor that represents the order of selection. And, Combinations means choosing all or only a part of a set of objects where the order of selection is not taken as a factor.