top button
Flag Notify
    Connect to us
      Facebook Login
      Site Registration

Facebook Login
Site Registration

How do you determine when it is exactly 9:15 PM?

0 votes
105 views

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?

posted Dec 1, 2015 by Sandeep Otari

Share this puzzle
Facebook Share Button Twitter Share Button LinkedIn Share Button

1 Answer

+1 vote
 
Best answer

Count the number of drops between the two rings of the church bells. This gives you the number of drops per hour. Divide that number by 4 to give you the drops per 15 min.

When diner is served, wait for the church bell to ring 3 times. At that time it is 19:00. Now count the number of drops. When it matches the number you calculated earlier, it is 19:15 and you should send the message.

answer Dec 3, 2015 by Jcm



Similar Puzzles
0 votes

Pawan asks Kashish, 'It is 9 pm as per my watch right now.
Do you know what will be the time 23, 999, 997 hours later?'

Kashish knows the answer. Do you ?

0 votes

A man is on a game show.
To win the game show and get a car, he must exit an empty room exactly one 1/2 hour later.
He is given one candle that lasts exactly one hour and a lighter.
Exactly 30 min later the man exits the room and wins his car.
How did he do it?

+1 vote

Lost in the woods, you come upon a mysterious stranger who hands you two large spheres made of two kinds of opaque marble. The spheres look the same, are the same size and have the same weight and apparent density; however, one is solid and the other hollow. The hollow sphere contains a tiny map that will enable you to navigate your way home. Unfortunately, you cannot break the spheres. The stranger agrees to open the sphere that contains the map only if you can determine which sphere is hollow.
How do you determine which sphere is hollow?

0 votes

What is the number if it divides exactly by 13 and when you write its digits in reverse order you make a square number. (You get a square number when you multiply a number by itself - 64 is square because it is 8 times 8)

0 votes

enter image description here

Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them.

Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it.

How will you do it?

...