Permutations

Hey Fam

So in class we started taking a look at permutations and how we can use it to help us solve problems that we may have that involve arrangement. A Permutation is to arrange or rearrange a set or collection of objects in a certain, specific order without repetition, unless stated.

We can solve permutation problems by using the dashed method, or the formula

      Formula: nPr = n!/(n-r)!
      "n" is equal to the total number of objects and entities
      while "r" is equal the amount of objects you pick

      This means that "n" must always be greater than "r"

Example

Question: A restaurant has 8 available tables for customers. If 5 different groups of people enter the restaurant, how many different ways can they be seated in the restaurant?

Answer:            nPr = n!/(n-r)!                                                   8P5 = 8!/(8-5)!

                          n = 8                                                                         = 8!/3!

                          r = 5                                                                          = 6720 different ways