Brain Teasers and Puzzles

In the UK, Soduko is currently quite popular - daily puzzles in the Telegraph & Times newspapers I believe. I wrote a program that solves these instantaneously, just using logic. On some puzzles, the two logic functions I repeatedly call may grind to a halt so I added a "guess" stage that takes a each possible value left for each unknown cell in turn and tries to continue logically. I have found that this has solved all the puzzles it has come across. On the Telegraph web page, there is a PDF guide where a "Truly diabolical" puzzle is defined as one where you have to "guess" at more than one stage. However, the example given can be solved by a single "guess s…

There are two glasses of water, one is 10 degrees above room temperature, the other 10 degrees below. The water in each glass is identical, glasses are identical, conditions for both glasses of water are identical as well. They are left in a room. Which glass of water will reach room temperature first? Why?

Albert is a keen dog admirer and over the years has had a number of dogs. He has had an Alsatian, a Dalmatian, a Poodle and a Great Dane, but not necessarily in that order. Albert had Jamie first. The Dalmatian was an adored pet before the Great Dane. Sammy, the Alsatian, was the second dog Albert loved. Whitney was housed before the Poodle and Jimmy was not a Great Dane. Can you tell each of the dogs' name and the order in which Albert had them?

When can a hundred to one be equal to fifty fifty?

This one is a pretty well known logic question, but probably the hardest of its kind I've come across... I figure I'll post it incase some people don't know about it Your in a hallway with two doors. One leads to hell, one leads to heaven. There is a guard standing by each door. One of the guards always tells the truth and the other one always lies. You have one question to ask, what will it be? (assuming you want to go to heaven) Thats the all info you have... Don't google it if you know any other ones that are harder than this post them up...

heres a puzzle my math teacher gave me a few years back. you just have to figure out what the next line will be. 1 11 21 1211 111221 312211 13112221 if you figure it out post the next line without giving the secret, i wanna see how long it can get

Been playing recently some puzzle I found on the net, the ones where you're in a room and you've got to get clues and find yourself out. I played one called "Crimson Room" which was OK, but by far the best is "The Mystery Of Time and Space" or just do a google search of MOTAS, and click the first link...could almost not sleep just to finish it, been giving me hours of fun.

This is one I made in about 1 min. It's all one word. 0001101001100111111 hint 4,3,4,4,4.

If a hen and a half lays an egg and a half in a day and a half, how many hens that are better by half lay a score and a half in a week and a half? I am an evil girl. The major part of the problem is translating it into mathematical notation.

Someone forwarded me a message with this website on it: http://www.mindreader.lx.ro There weren't a lot of people on the list, so I think that it may be pretty new. Anyway, it is a fake. How long will it take you to figure out how it works?

I don't know if there is an answer to this...just see if you can think of an ingenious solution! You want to know your weight, but you only have a set of electronic kitchen scales that only weighs items up to 5 kilograms. How do you use these scales to determine your weight?

10,1,21,12,34,43,51,15,70,7, ?

61 52 xx 94 46 xx =

Blank i don't exactly know what they talk about and i suspect neither do they but i think i know what it sounds like. sort of like a riff in between transitions and i seem to recognize it best in the sound a good regiment makes when it breaks stride so as not to shake a little bridge down. doyano what i mean?

Someone posted this at another forum, and I found it intersting to share: Once upon a time a king wanted to hire the best Mathematician in his kingdom to work in his palace. His servants brought to him the best two mathematicians, one of them was blind. The king told both mathematicians that he can't hire both so he will ask a question and whoever answers gets the job. The king said: "I have three sons, whoever guesses their ages will be hired." The king told them that if they multiply the ages of his sons the result will be 36. Both mathematicians told the king that this information is not enough. The king then said: "The number of windows in the building across…

Tom is a very large fellow, who is also a fishmonger. What does he weigh?

14, 23, 8, 15, 9, X X = ?

This isn't a math or science brain teaser but it's been bugging me just the same. I was at a friend's house last night and they were playing this game. You set it up by taking 2 people and 2 long ropes. Each end of Rope 1 is tied to a wrist of the first guy. Rope 2 is tied to the wrist of the second guy then fed through the loop formed from the first rope and tied to his other wrist. Without being as specific, the players are connected - the ropes are looped together. The point is to somehow separate. According to my friend, the connection at the wrists could be permanent and the rope could be impossible to cut - and it would still work. I'm not one to ca…

Here we go... A fly is flying about, minding its own business. However he does not realise he is on a direct collision course towards ano on coming train. Now neglecting air resistance, when he hits the train he becomes a part of it right? At that very same moment he must change his direction. However in order to change direction he must STOP, now as he is part of the train the train must also STOP for that brief second.... Therefore a fly can stop a train, now where is the flaw in this argument....?

What's the toughest science-related riddle you've come across? Post any humorous or difficult riddles here.

Make an equation out of these numbers and symbols. You may only use each once. 2 3 4 5 + =

Can anyone tell me the maximum limit to this sequence? It was given as a challenge at my school. 3,8,12,15,17,18,24.5,28.5,33,35,43.5,48.666,51.666........ The prize is " Free Chocolates".

Just using addition, subtraction, multiplication, and division, can you form all the numbers from 1 to 10 using exactly four 4's? You may use parentheses and you can also combine fours to make other numbers (like 44 or 444).

lets see who can work this out, 0= space too. 8,44,444,7777,0,444,7777,0,2,0,8,99,8,0,6,7777,6. it`s really quite simple

Hi all, Does anyone know or remember the complete version of 'Ballon Game' question ? The following are some hints: - There are 7 people who ride a Helium Balloon across the sea. - 7 people consist of Bankir, Male Model, Pregnant Woman, Police etc (I forgot the others) - The sea was fulfilled with many sharks. - The Helium Balloon was almost fall into the sea. - The question: Who should jump into the sea first or in the sequence? - This question doesn't have correct answer. Any comments I appreciate it. Thank's -wawan-