List your choices in order with the favorite on top an

1
Ordinal Ballots

• Preference Schedule
• Preference List

2
Ordinal Ballots

• List your choices in order with the favorite on
  top and least favorite on bottom
• Ballots must be
• Complete (you must rank all candidates)
• Linear (no ties)
• Transitive (If you prefer A to B and B to C, then
  you must prefer A to C.)

3
How many different ordinal ballots are possible?

• Try this first for two candidates A and B.
• Next try it for three candidates A, B and C.
• What about for four candidates A,B,C and D?
• Can you see a pattern to the numbers? What is it?

4
Factorials

• 1! 1
• 2! 12 2
• 3! 123 6
• 4! 1234 24
• Etc.
• Note 0! is defined to be 1.

5
TV Program Vote Again

• Vote again for The Office, Family Guy and The
  Mentalist, this time making a preference list
  with your top choice on top.
• How many possible lists will there be?