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Numbers in a square Patterns and correspondences  Weight: 1 Liked the puzzle: 75% 24.12.2011
Place numbers 1,2,.., 9 without repetitions into a 3x3 square so that the sums in all rows, columns, and diagonals are all equal.
Comments:  1 | check your solution  
A 100 M&Ms Puzzles for children  Weight: 1 Liked the puzzle: 100% 02.01.2010
A Megamind has two bags and 100 M&Ms. He needs to put all the candies into the bags so that one bag has twice as many M&Ms as the other. He cannot split the M&Ms. What should the Megamind do?
Comments:  11 | check your solution  
Six glasses Puzzles for children  Weight: 1 Liked the puzzle: 100% 22.01.2011
A row of six glasses is on a table. Three full glasses are followed by three empty glasses. Is it possible to make these glasses alternate: full,empty full, etc by touching only one glass?
Comments:  3 | check your solution  
Links and chains Logic puzzles  Weight: 1 Liked the puzzle: 100% 02.04.2011
Once upon a time, a Megamind worked as a smith. He was brought 5 chains each consisting of 3 links. What is the minimal number of links that the Megamind should re-lock to make one long chain?
Comments:  1 | check your solution  
Obtain 24 Algebra, arithmetic  Weight: 2 Liked the puzzle: 100% 27.12.2009
Using numbers 1,3,4,6, and basic arithmetic operations (addition, subtraction, multiplication, and division) and parentheses, obtain and expression that evaluates to 24. You may use only these numbers and only these operations. Every number should be used exactly once. Numbers cannot be concatenated, i.e. you cannot use 13 or 146.
Comments:  7 | check your solution  
Milk, lemonade, water, and coke Patterns and correspondences  Weight: 2 Liked the puzzle: 100% 27.01.2011
A bottle,a glass, a carafe, and a can contain milk, lemonade, water, and coke. Water and milk are not in the bottle. The container with lemonade is immediately between the carafe and the container with coke. The can does not contain lemonade or water. The glass is next to the can and the container with milk. The containers form a row. How exactly are they arranged?
Comments:  4 | check your solution  
Two villages Knights, Knaves and Jokers  Weight: 2 Liked the puzzle: 100% 27.12.2009
A Megamind is lost in the mountains. He is standing on a path, shouting for help. Finally, he sees a local approaching. Megamind knows that the locals can be knights that always tell the truth, or knaves that always lie. He also knows that the path leads to the village of knights in one direction and to the village of knaves in the other. The problems is that the knaves are also hateful of Megaminds, and will stone him if gets to their village. How can Megamind ask one question and determine the right way to go?
Comments:  4 | check your solution  
101 coins Weighing puzzles  Weight: 3 Liked the puzzle: 100% 04.01.2010
Among 101 coins, exactly 50 are counterfeit. A counterfeit coins weighs one gram more or gram less than the real coin (counterfeit coins may weigh differently). You have a balance scale that shows the exact weight differential between the two cups. How can you determine whether a given coin from this set is counterfeit using the scale only once?
Comments:  1 | check your solution  
50 coins Logic puzzles  Weight: 3 Liked the puzzle: 100% 27.12.2009
Once upon a time, a tsar was holding a reception and the Megamind was among the guests. The tsar decided to test how smart the Megamind was, took him into a dark room, and gave the following task: On the table in this room, there are 50 coins, exactly 10 of them are tails up. In the darkness, it is impossible to determine the sides of these coins. Touching the coins also does not help. The Megamind has to separate these coins into two groups so that the number of tails in both are equal. Can he do it?
Comments:  4 | check your solution  
Weights Weighing puzzles  Weight: 3 Liked the puzzle: 100% 29.01.2010
What is the minimal number of weights required to be able to balance all integer weights 1,2,...,40 on a balance scale? Justify the minimality.
Comments:  4 | check your solution  
A game with coins Games puzzles  Weight: 4 Liked the puzzle: 100% 12.03.2011
Two Megaminds play a game: they have a regular round table and an unlimited supply of identical round coins. Turn by turn, they place coins on the table until someone can no longer make a move. The coins cannot overlay each other, but they can touch. Who has a winning strategy (and what is it) in this game?
Comments:  5 | check your solution  
Six matches and triangles 2 Geometry puzzles  Weight: 4 Liked the puzzle: 100% 07.02.2010
How to make one equilateral and three isosceles (and not equilateral!) triangles using 6 sticks of the same length? Sticks cannot be broken and/or laid over each other and no free ends of the matches may be left.
Comments:  1 | check your solution  
12 coins Weighing puzzles  Weight: 4 Liked the puzzle: 100% 03.02.2010
A Megamind has 12 coins, one of which is counterfeit and weighs differently from the others. He has a balance scale, but no weights. How can the Megamind find the counterfeit coin and determine whether it is lighter or heavier than the standard ones? What is the minimal number of weighings required?
Comments:  1 | check your solution  
A foreign sentry Knights, Knaves and Jokers  Weight: 5 Liked the puzzle: 100% 04.01.2010
You are standing at the road fork. One of the two roads leads to your destination, but you don't know which one. Fortunately, there is a sentry guarding the intersection. Unfortunately, the sentry can be a knight or a knave, moreover, he is a foreigner. He understands you, but when he responds, he says "uhh" or "err" meaning "yes" or "no", but you don't know what means what. He does not say anything else, and he is standing at attention, not being able to point in the right direction. On top of all this, the sentry is somewhat dumb, i.e. he cannot understand sentences longer than 13 words. You may ask a single question to figure out which way to go. Which question should you ask?
Comments:  1 | check your solution  
A game with wooden sticks Games puzzles  Weight: 5 Liked the puzzle: 100% 02.01.2010
Two MegaMinds play a game with 100 wooden sticks. The lengths of the sticks are 1,2,3,...,100 inches. Turn by turn, the players choose three of the remaining sticks which form a triangle, and burn them. The player that cannot make a move loses. Which player has a winning strategy (justify your answer)?
Comments:  3 | check your solution  
Divide a parallelogram Geometry puzzles  Weight: 5 Liked the puzzle: 100% 02.04.2011
How to divide a parallelogram into 9 isosceles triangles?
Comments:  1 | check your solution  



 
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