Locks for a four-of-seven safe
A firm's employees want a safe that opens only when at least of them agree. They install locks, distributing keys so that every group of can open all locks but no group of can. What is the minimum number of locks required?
Show hints (2)+
- Each group of must be locked out by some lock whose key they all lack.
- One lock per -subset (keys to the other ): .
Answer
Reveal answer →Final answer
35
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Asked at: Jane Street, Two Sigma