Solution One-one function from {1, 2, 3} to itself is simply a permutation on three
symbols 1, 2, 3 Therefore, total number of one-one maps from {1, 2, 3} to itself is
same as total number of permutations on three symbols 1, 2, 3 which is 3 = 6 Example 23 Let A = {1, 2, 3}