Hard
Expert Riddles
20 XP

The Dropped Ball

8,183 solved 74% solve rate 26% fail rate
You have 2 identical crystal balls and a 100-story building. What is the minimum number of drops needed to find the exact floor where the ball breaks (worst case)?
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8,183 attempts
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Quick Answer & Explanation
14 drops. Start at

The answer to this riddle is 14 drops. Start at. Difficulty: Hard · Solved by 8,183 puzzle lovers.

14 drops. Start at floor 14. If it breaks, test floors 1-13 linearly. If not, jump to 27 (14+13), then 39, etc. Each jump decreases by 1.
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