Class 11 Maths Chapter 6 Permutations and Combinations – Exercise 6.2 NCERT Solutions Introduction Exercise 6.2 introduces the concept of combinations. Unlike permutations, combinations focus on selections where order does not matter. You will learn how to calculate the number of ways to choose objects from a set and apply these ideas to practical problems. Key Concepts Combination Formula: Number of combinations of n objects taken r at a time: C ( n , r ) = ( n r ) = n ! r ! ( n − r ) ! Properties of Combinations: ( n 0 ) = 1 ( n n ) = 1 ( n r ) = ( n n − r ) Difference from Permutations: Permutations: order matters. Combinations: order does not matter. NCERT Questions with Solutions (10) Q1. Find number of combinations of 5 objects taken 3 at a time. C ( 5 , 3 ) = 5 ! 3 ! ⋅ 2 ! = 120 12 = 10 Q2. Find number of combinations of 6 objects taken 2 at a time. C ( 6 , 2 ) = 6 ! 2 ! ⋅ 4 ! = 720 48 = 15 Q3. Find number of combinations of 4 objects taken all at a time. C ( 4 , 4 ) = 1 Q4....