# Zero Factorial: Why is 0! = 1?

This video provides justification as to why 0!=1 using patterns and the meaning of a permutation.

# Ex: Determine a Probability Using a Permuation – Match Phone Digits

This video explains how to determine the probability of randomly selected digits matching three digits of a phone number.

# Ex: Determine the Possible Number of Ways 255 Contestants can Win 3 Prizes (Permutation)

This video explains how to determine the number of ways 255 contestants can win a 1st, 2nd, and 3rd place prize.  A permutation and the counting principle are used.

# Ex: Determine the Possible Number of 4 Color Striped Flags (Permutation)

This video explains how to find the number flags with 4 stripes of different colors.  A permutation and the counting principle is used.

# Ex: Deterine the Number of Ways Six Runners Can Finish – Counting/Permutation

This video explains how to determine the number of ways six runners can finish using the counting principles and a permutation.

# Ex: Evaluate a Combination and a Permutation – (n,r)

This video explains how to evaluate a combination and a permutation with the same value of n and r.

# Ex: Evaluate a Combination and a Permutation – (n,1)

This video explains how to evaluate a combination and a permutation with the same value of n and r = 1.