Answer:

Explanation:
This problem models a geomatric sequence, because each new element is half of the last one.
A geometric sequence is defined as

Where
is the position of the element,
is the first element and
is the reason that creates the sequence.
In this case, we have
,

Replacing this values, we have

Where
is the independent variable and
is the dependent variable.
Therefore, the function that relates the number of rounds and the number of players advaincing to the next round is
