Problema Solution

Each year the local country club sponsors a tennis tournament. Play starts with 128 participants. During each round, half of the players are eliminated. How many players remain after 5 rounds.

Answer provided by our tutors

After 1st round there are: 128/2 = 64 players left

After 2nd round there are: 64/2 = 32 players left

After 3rd round there are: 32/2 = 16 players left

After 4th round there are: 16/2 = 8 players left

After 5th round there are: 8/2 = 4 players left

Or in general after n rounds there are: 128/(2^n) players left.

In our case n = 5 and 128/(2^5) = 128/32 = 4 players left.