Brain Teasers
Lock and Key
You want to send a valuable object to a friend. You have a box which is more than large enough to contain the object. You have several locks with keys. The box has a locking ring which is more than large enough to have a lock attached. But your friend does not have the key to any lock that you have. Note that you cannot send a key in an unlocked box, since it might be copied. How do you do it?
Answer
Attach a lock to the ring. Send it to her. She attaches her own lock and sends it back. You remove your lock and send it back to her. She removes her lock.Hide Answer Show Answer
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Comments
You could do it this way but by the time you have paid for postage and everything it would have been cheaper to go and take it to the friend personally. nobody would do it this way.
an interesting one.
Let sya that I wanted to send this item to either dsquared or glennyboy. Yes I would use this method. i am in England and they are on the other side of the world. I would not take it to them myself as I am just a titchy bit scared witless of spiders and snakes, and it wont work telling me there are none in that part of the country! Yes I would use that method.
I love this sort of teaser! It has a definite solution, and though it takes a bit of thought, it can be done without any special knowledge. Fun stuff!
Why wouldn't you just ask your friend to mail you a lock, then use that on the box when you send it to her? Why would you risk sending valuable property through the mail 3 times instead of once?
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