In this tutorial I show you what we mean by a permutation, and how to work them out for n different items. You are also given 3 questions to answer.
(1) In how many different ways can you arrange 6 people in a line?
(2) How many different numbers can be formed from the digits 1, 2, 3, 4, 5, 6 and 7 if each digit is used only once?
(3) How many different car registration plates can be made consisting of the letters A, B and C, the numbers 1, 2, 3 and 4 where the 3 letters appear before the four numbers and each number and letter can appear once in each registration plate?

Permutations of n different items : ExamSolutions Maths Revision - youtube Video