## The 99 Balls Game: A Classic Puzzle with a Twist
The 99 Balls Game is a popular brain teaser that tests your logic and problem-solving skills. While seemingly simple, it can be surprisingly challenging, requiring you to think outside the box and employ a bit of strategy.
The Challenge:
Imagine you have 99 balls, 98 of which are identical, and one unique ball. You have a scale, but it can only be used three times. Your goal: Identify the unique ball.
The Solution:
Here's how to solve the 99 Balls puzzle:
1. First Weighing: Divide the balls into three groups: 33 balls in each group. Place group 1 on one side of the scale and group 2 on the other.
* Scenario 1: If the scale balances, the unique ball is in the remaining group of 33.
* Scenario 2: If the scale tips, the unique ball is in the group on the heavier side.
2. Second Weighing: Take the group containing the unique ball and divide it into three groups of 11. Place group 1 on one side of the scale and group 2 on the other.
* Scenario 1: If the scale balances, the unique ball is in the remaining group of 11.
* Scenario 2: If the scale tips, the unique ball is in the group on the heavier side.
3. Third Weighing: Take the group of 11 balls and choose any two balls. Place one on each side of the scale.
* Scenario 1: If the scale tips, the unique ball is the heavier one.
* Scenario 2: If the scale balances, the remaining ball from the group of 11 is the unique one.
Why This Works:
The puzzle is based on the concept of repeatedly dividing the possibilities in half. Each weighing eliminates a significant portion of the potential balls, narrowing the search until you isolate the unique one.
Variations and Extensions:
The 99 Balls Game has many variations, including:
* Different Number of Balls: The puzzle can be adapted to use any number of balls, with the number of weighings adjusting accordingly.
* Different Number of Unique Balls: You can introduce more than one unique ball, making the puzzle even more complex.
* More Constraints: The puzzle can be further challenged by adding constraints, such as limitations on the number of balls that can be placed on the scale at once.
The Takeaway:
The 99 Balls Game isn't just a puzzle; it's a lesson in efficient problem-solving. It teaches us to break down complex problems into smaller, manageable steps, and to use strategic thinking to find solutions. So next time you encounter a seemingly daunting task, remember the 99 Balls Game, and think about how you can use a process of elimination to reach your goal.