A knockout tennis tournament is held between eight talented players, including the two twins Kerry and Kelly.

The eight players are each evenly matched, and the players pull their names out of a hat to determine who goes where on the ladder in the first round.

1. What is the chance that Kerry and Kelly play each other at some point in the tournament?
2. What if there are 16 players? 32 players? 2ⁿ players?