An old man, with four sons and three daughters, buried a safebox with valuables inside. He wanted his children to get it when he died, but neither the boys nor the girls to get it all for themselves; he desired that at least two sons and two daughters had to be involved in order to find the missing treasure.

(For example, the three girls on their own couldn't find the treasure, even if one boy helped them. The four boys and one girl couldn't find it either.)

How could he manage this?

I believe that I've encountered something akin to this in "The Code Book" by Simon Singh except that a designated number of persons from within the larger set had to be present.

In that case 4(?) keys were replicated and passed around so that 4 people had to be present to open it.

In this case, there would need to be 4(?) different instructions distributed in such a way to ensure that no 3 persons could have the solution.

***
Since my earlier post, above the stars, I've played with some situations.

One must discriminate between the genders (sorry nikki) to ensure the balance; I've been tempted to go to the book (mentioned above) to see that solution.  I'm now thinking 5 instructions of which each get 3.

Edited on July 17, 2005, 3:40 am

Posted by brianjn on 2005-07-17 02:51:28