Lock Puzzle. Hope this is not posted before in this section!
There is your friend in a faraway place. And we are in a time where the only means of communication is through post. There is no phone, courier, travelling to that place etc.,
Now, there is 1 precious item that you have to send it to your friend through post. All that you have got is a Multi-lock box (box on which u can apply more than 1 lock). You have to send that precious item, only through this box. There are many robbers in between, who can steal the item if you do not lock the box or send the key along. How will you make sure that your friend receives that precious item?????????