I hate sails math- like what is the point of it? -_-

Awrestling tournament begins with 128 competitors. in the first round, each competitor has 1 match against another wrestler. the winner of each match moves on to the next round until there is a winner. write a sequence in which the terms represent the number of players still in the tournament at the end of each round. describe the sequence? how many rounds are in the tournament?

In two or more complete sentences describe how to determine the appropriate model for the set of data, (1,1), (3,2), (6,3), (11,4).

What is the y intercept of f(x)=(1/2)^x?