Braingle: 'Jail Message' Brain Teaser

Jail Message

Logic puzzles require you to think. You will have to be logical in your reasoning.

Puzzle ID:	#36469
Fun:	(2.96)
Difficulty:	(2.12)
Category:	Logic
Submitted By:	LeafFan4life
Corrected By:	drussel3

You are locked in a jail cell with no windows, and you need to tap out a message on the wall for the man in the other cell next to you. The problem is that you have to do it at exactly 9:15 PM, when the guard outside is switched, so your noise won't be noticed. You can't hear the switching of the guards through your walls, and you have no clock.

There is a faucet with water dripping very consistently from it in the corner, but you don't know if it is dripping at 30 or 40 or however many drops per minute, and that wouldn't give you the time in any case. You can just make out the chiming of a church bell, but it chimes just once at the top of each hour, so you can't tell the time from that. You can feel the wall facing west start to cool after the sun sets, but you don't know what time the sun is setting, and this isn't very precise in any case. Your dinner is always passed into your cell between 6:15 and 6:45. How do you determine when it is exactly 9:15 PM?

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Comments

vlerma Apr 30, 2007	Well never having been in jail I had to read your teaser several times. Not inferring that you have been But after reading it through several times I figured out the answer. Good job. Made me work for it.
Waterpelt Apr 30, 2007	Nice Teaser Really hard math
HarryPutter Apr 30, 2007	lol leaffan4life that karma thing happened to you again LOL who keeps blacklisting u?
HarryPutter Apr 30, 2007	btw nice teaser i feel sorry for you evrytime u get ur karma up some1 blacklists u
nerdyiscool Apr 30, 2007	I didn't get it, but now I have 50 teaser votes! Yaaaay me!
UnDeFeAtEd Apr 30, 2007	since some1 keeps blacklisting my actual account(leaffan4life) i cant post comments with it so I ll use this account to thank every1 for the comments they are leaving PS:thank you harry i see you sincerity in your comments lol
HarryPutter May 01, 2007	lol
notsosmart111 May 01, 2007	i love that it is going on my favorites
scallio May 02, 2007	Fairly easy teaser but very unique. I enjoyed this thoroughly! I always love a good logic teaser, but this was most excellent due to its originality.
scallio May 02, 2007	On the subject of bad karma-- I never see bad comments from you. Your bad karma has made me quite curious. How does one earn bad karma other than making rude comments? By the way- I have no problem with someone stating they don't care for a teaser or thinking it is too easy, etc. We shouldn't lie about liking a terrible teaser. The key is in wording it correctly without personal attacks on the author. For example, one might state that a teaser is poorly written without saying it was utterly stupid. One might say a teaser is too easy without saying it could have been written by a first grader. Hmmm...
liser May 02, 2007	Very original! I'm always impressed when someone takes the time to think through something like this and create such an original teaser. Well done!
Tryer May 02, 2007	My mind boggles how clever you are to think up these Full marks from me... sorry to hear that somebody is treating you unfairly
saxman May 03, 2007	Waterpelt - I would say that, with out having the water drops physically here, teh math was impossible, so, yeah, I gouess you could say it was really hard. I liked the red herring about the west wall cooling. But, overall - I thought it was a nice question. It is the kind of questions that are on the Practice of Engineering Examination.
IluvDepp_Bloom May 13, 2007	too hard! sorry!
jin10doh May 17, 2007	Interesting scenario... However, there's a much easier way to figure out when it's 9:15. Figuring out the hour was simple enough with the chimes ringing every hour. But, instead of having to count droplets of water for a WHOLE hour, why not wait until the third chime after dinner then just count the seconds until you reach 15 minutes? Counting droplets of water for an hour is so much more difficult than counting out 900 seconds. Would this count as still getting the riddle wrong...?
rose996 May 23, 2007	very creative but it wouldn't work. Water droplets do not measure out to the same size with every drop and because of this the speed of the drops would vary. It would be much easier to count the hours from dinner to 9 and then the minutes(seconds) from there
LeafFan4life May 23, 2007	ok
zembobo May 28, 2007	jin10doh, why don't you try counting out 15 minutes. See how hard it is to be accurate. Start a stop watch and set it face down and start your counting. After you THINK you've reach 15 mintues, look at the stop watch. I'll bet you'll be off by at least 2-3 minutes.
MikeMan1216 May 29, 2007	Very nice teaser.
kit_maree May 31, 2007	loved it figured it out first go!! brilliant, i love teasers like this because you have to use math and creative thinking
_brynn Jun 07, 2007	haha that was cool
drussel3 Jun 18, 2007	Nice One.
kaligali Jun 19, 2007	wow that's a cool one!
Fhempen Jul 04, 2007	wow. very original and very cool i got it on the first try, but i loved it! very very very well done
leftclick Jul 08, 2007	Really nice teaser, if a bit easy
meg19_83 Jul 19, 2007	it was alright
spinnercat Jul 22, 2007	way too easy. You don't even have to count drips between 8 and 9, you could do any hour.
ava199345 Jul 29, 2007	I'll keep this in mind if I'm ever in jail.
luckypuppy Aug 16, 2007	yes, you could count the drops any hour, the only thing is to keep track of the chimes after dinner
Scorefire Nov 27, 2010	I thought that you could count how many drops after the bell chimes before dinner (at 6:15), then, after it's 90, then you could count how many times the water drops after that, the same amount of drops you counted before...
princess2007 Feb 23, 2013	Um, a little easier than I like but great fun!