Time Spent In Jail
Posted by Rajesh Lal on March 30, 2010 – 8:30 pm
Ragknot has been imprisoned in a jail cell with no windows, he needs to tap out a message on the wall for Zaux in the other cell next to him to help plan their escape.
The problem is that he has to do it at exactly 9:15 PM, when the guard outside is switched, so the noise won’t be noticed. He can’t hear the switching of the guards through the walls, and he has no clock.
There is a faucet with water dripping very consistently from it in the corner, he can just make out the chiming of a church bell, but it chimes just once at the top of each hour, so he can’t tell the time from that. He can feel the wall facing west start to cool after the sun sets, but he doesn’t know what time the sun is setting, and this isn’t very precise in any case.
His dinner is always passed into your cell between 6:15 and 6:45. How does he determine when it is exactly 9:15 PM?
- Karl Sharman