Answer:
63 games are played.
In the bracket at each stage of the game you have 2 choices.
so total 2^63 ways are there to fill out the bracket.
2^63 = 9,223,372,036,854,775,808 which is approx. 9.2 Quintillion.
Number of people in USA= 317,431,148.
So all possible outcomes of bracket filling to be represented, each person should fill out following number of brackets.
9,223,372,036,854,775,808
= -------------------------------------- = 29,056,291,718.6
317,431,148
which is approximately 29,056,291,719 brackets per person.
Explanation: