Shmoop University
Shmoop: Basic Statistics & Probability: Factorials
The probability resource investigates factorials. Students learn about the topic through notes and examples. The tutorial consists of practice exercises to check for comprehension of the concept.
Wolfram Research
Wolfram Math World: Topics of Permutation
This MathWorld site is a lite to link to a multitude of sites involving permutations. Look through to find your specific needs. If you are looking at this site with regards to a probability and statisics class you will probably want to...
Other
Lake Tahoe Com. College: Fundamental Counting Principle
Explains the fundamental principle of counting, which is the beginning point for any study of counting techniques such as combinations and permutations.