Final answer:
To find the number of rounds needed until the players reach the semifinals with four players left, we can set up an equation using exponential growth. After solving the equation, we find that 4 rounds must be played.
Step-by-step explanation:
To find the number of rounds needed until the players reach the semifinals with four players left, we can set up an equation using exponential growth.
Initially, there are 64 players.
After each round, half of the players are eliminated, which means the number of players is halved.
Let x represent the number of rounds needed.
So the equation is: 64 / 2ˣ = 4.
We can solve this equation by equating the exponent of 2 on both sides:
2ˣ = 64 / 4 = 16.
Taking the logarithm base 2 of both sides, we get:
x = log2(16) = 4.
Therefore, 4 rounds must be played until the players reach the semifinals with four players left.