Suppose five pirates have one chest with clasp through which can be threaded many padlocks, many padlocks with keys[1], and a key-cutting machine. They wish to lock the chest such that any three of them may open the chest (but fewer can't). How can they do this? What is the fewest number of padlocks necessary?
[1] Assume each padlock starts with only one key, but the key can be duplicated so several pirates can have a key to the same padlock. Label each padlock 125 if only pirates 1,2 and 5 have a key for it.
( Answers and speculation )
[1] Assume each padlock starts with only one key, but the key can be duplicated so several pirates can have a key to the same padlock. Label each padlock 125 if only pirates 1,2 and 5 have a key for it.
( Answers and speculation )