●●● ●●●● ●●●●● ●●●● ●●0●● Basic Counting Techniques ●●●● ●●●● ● Permutations o a permutation is an arrangement of n items where every item appears exactly once o There are n! different permutations o 2-1 sn! sn-1=====> n! is a very large number 232 4,294.967296 10!=3,628800 11!=39916800 12!=479,001.600 13!=6,227,020,800>2326 Basic Counting Techniques ⚫ Permutations ⚫ A permutation is an arrangement of n items, where every item appears exactly once. ⚫ There are n! different permutations. ⚫ 2 n-1 ≤ n! ≤ nn-1 =====> n! is a very large number. ⚫ 2 32 = 4,294,967,296 ⚫ 10! = 3,628,800 ⚫ 11! = 39,916,800 ⚫ 12! = 479,001,600 ⚫ 13! = 6,227,020,800 > 232