Jan and Maria have fallen in love (via the internet) and Jan wishes to mail her a ring. Unfortunately, they live in the country of Kleptopia where anything sent through the mail will be stolen unless it is enclosed in a padlocked box. Jan and Maria each have plenty of padlocks, but none to which the other has a key. How can Jan get the ring safely into Maria’s hands?
This puzzle came from Caroline Calderbank, young daughter of mathematicians Ingrid Daubechies
and Rob Calderbank.
In the solution she had in mind, Jan sends Maria a box with the ring in
it and one of his padlocks on it. Upon receipt Maria affixes her own padlock to box and mails it
back with both padlocks on it. When Jan gets it he removes his padlock and sends the box back to
Maria; voila!
No comments:
Post a Comment