Idon't really understand if you could just give me the answer that would be amazing

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?

What is the volume of the sphere shown below with a radius of 3?

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')