A group of five people want to put a set of locks on a chest and distribute keys to the locks amongst themselves in such a way that all the locks on the chest could be opened only when at least three of them were present to open it.
How many locks would be needed, and how many keys?
(In reply to Explanations
Gamer is absolutely correct.
It should go without saying that a solution is not a full solution if
it does not only demonstrate the answer, but also the means to the