What Is Permutation: A permutation is an arrangement of objects in a definite order. Real Life Example of Permutation: 1. Protein Formation in The Body. 2. Working Out the Ways to Win a Lottery. 3. Number of Seating Arrangements. Permutation of n different objects: A permutation of n objects taken k at a time is an arrangement of k of the n objects in a specific order where 0 < r ≤ n. The symbol for this number is P (n, k).