Permutations

09/15/15

 Today we were introduced to permutations and how to permute a set of objects. A permutation is all the possible arrangements of a set of objects where order is important. In order to use the permutation formula thenquestion must not allow restrictions or repetitions. If there are restrictions and/or repetitions you may use the dash method.

The formula for permutations: nPr = n!/ (n-r)!
reminder: ! is the factorial symbol
                     n= total amount of objects to arrange
                     r= amount of objects taken at a given time

Example

Q: A class of 8 people that were consisted of 4 male students and 4 female students were lined up to be photographed. How many arrangements or different photographs can be taken?

A: n=8  r=8

8P8
=8! / (8-8)!
=8!
=40,320