
1. 
pretorik 
 
161 
2. 
markr 
 
116 
3. 
Gordon Weir 
 
104 
4. 
mbloomfi 
 
97 
5. 
Dennis Nazarov 
 
96 
6. 
zzz123 
 
72 
7. 
Srikanta 
 
56 
8. 
lidSpelunker 
 
53 
9. 
SAMIH FAHMY 
 
48 
10. 
jkr 
 
44 




1. 
denisR, mishik 
 
236 
2. 
alan, De_Bill 
 
231 
3. 
dddfff 
 
228 
4. 
kavfy 
 
221 
5. 
idler_ 
 
106 
6. 
akajobe 
 
94 
7. 
tolstyi 
 
56 
8. 
STARuK 
 
42 
9. 
vale 
 
31 
10. 
xandr 
 
11 





Place numbers 1,2,.., 9 without repetitions into a 3x3 square so that
the sums in all rows, columns, and diagonals are all equal. 


Puzzle statistics "Numbers in a square".
Last updated minutes ago.

Solved by:
Daily average:
Answers submitted:
Viewed by:
Fraction solved by: %
Solved at first attempt: %
Average discussion length:
Liked the puzzle:
Did not like the puzzle:
0


A Megamind has ordered a set of steel balls for his scientific
experiments: 2 red, 2 orange, 2 yellow, 2 green, and 2 blue.
The order was fulfilled but the balls of some color were made 1g
lighter than the others. The Megamind has a balance scale
that shows the exact weight differential between the two cups. He
needs to determine the defective color using one weighing.
Please, help the Megamind to do this. 


Puzzle statistics "Defective balls".
Last updated 5332161.3 minutes ago.

Solved by: 22
Daily average: 0
Answers submitted: 24
Viewed by: 257
Fraction solved by: 8.5%
Solved at first attempt: 95.4%
Average discussion length: 1.1
Liked the puzzle: 7
Did not like the puzzle:
0

Two incense sticks 
Logic puzzles 

Weight: 1 

Liked the puzzle: 100% 

27.12.2009 

You have two incense sticks, that burn unevenly, and a lighter. Each
will burn for an hour. How can you time 45 minutes using nothing but
these tools. 


Puzzle statistics "Two incense sticks".
Last updated 5332161.3 minutes ago.

Solved by: 41
Daily average: 0
Answers submitted: 53
Viewed by: 296
Fraction solved by: 13.8%
Solved at first attempt: 92.6%
Average discussion length: 1.1
Liked the puzzle: 11
Did not like the puzzle:
0


You have 8 coins that appear to be identical, except one (which is
counterfeit) is slightly heavier than the others. What is the
minimal number of weighings on the balance scale that is required to
find the counterfeit coin? 


Puzzle statistics "8 coins".
Last updated 5332161.3 minutes ago.

Solved by: 48
Daily average: 0.01
Answers submitted: 89
Viewed by: 295
Fraction solved by: 16.2%
Solved at first attempt: 72.9%
Average discussion length: 1.8
Liked the puzzle: 10
Did not like the puzzle:
0


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. 


Puzzle statistics "Obtain 24".
Last updated 5332161.3 minutes ago.

Solved by: 48
Daily average: 0.01
Answers submitted: 55
Viewed by: 296
Fraction solved by: 16.2%
Solved at first attempt: 87.5%
Average discussion length: 1.2
Liked the puzzle: 13
Did not like the puzzle:
0


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? 


Puzzle statistics "Milk, lemonade, water, and coke".
Last updated 5332161.3 minutes ago.

Solved by: 19
Daily average: 0
Answers submitted: 21
Viewed by: 259
Fraction solved by: 7.3%
Solved at first attempt: 78.9%
Average discussion length: 1.4
Liked the puzzle: 4
Did not like the puzzle:
0


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? 


Puzzle statistics "Two villages".
Last updated 5332161.3 minutes ago.

Solved by: 37
Daily average: 0
Answers submitted: 47
Viewed by: 296
Fraction solved by: 12.5%
Solved at first attempt: 83.7%
Average discussion length: 1.4
Liked the puzzle: 11
Did not like the puzzle:
0


The set of numbers 1,3,8,120 has a remarkable property: the product of
any two numbers is a perfect square minus one. Find a fifth number
that could be added to the set preserving its property. 


Puzzle statistics "The fifth number".
Last updated 5332161.3 minutes ago.

Solved by: 37
Daily average: 0
Answers submitted: 41
Viewed by: 291
Fraction solved by: 12.7%
Solved at first attempt: 97.2%
Average discussion length: 1.1
Liked the puzzle: 11
Did not like the puzzle:
0

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? 


Puzzle statistics "50 coins".
Last updated 5332161.3 minutes ago.

Solved by: 22
Daily average: 0
Answers submitted: 30
Viewed by: 296
Fraction solved by: 7.4%
Solved at first attempt: 90.9%
Average discussion length: 1.2
Liked the puzzle: 8
Did not like the puzzle:
0


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. 


Puzzle statistics "Weights".
Last updated 5332161.3 minutes ago.

Solved by: 9
Daily average: 0
Answers submitted: 17
Viewed by: 274
Fraction solved by: 3.2%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 2
Did not like the puzzle:
0


After a shipwreck, a MegaMind found himself on an island where some natives always lie and some always tell the truth. As a ritual, all natives stood in a circle facing the center, joined their hands and everybody told the MegaMind whether his right hand side neighbor is a liar or a truthteller. Based on this information, the MegaMind was able to determine the exact percentage of natives that tell the truth.
Can you also determine this percentage? 


Puzzle statistics "A circle of lies".
Last updated 5332161.3 minutes ago.

Solved by: 9
Daily average: 0
Answers submitted: 10
Viewed by: 284
Fraction solved by: 3.1%
Solved at first attempt: 77.7%
Average discussion length: 1.8
Liked the puzzle: 2
Did not like the puzzle:
0

The mouse hunt 
Games puzzles 

Weight: 4 

Liked the puzzle: 100% 

11.01.2010 

A smart cat named Leopold is hunting a mouse. A mouse is hiding in one
of five holes arranged in a row. Leopold can reach into one of the
holes and try to catch the mouse. If he is not successful, the scared
mouse runs into a right/left neighboring hole. Is it guaranteed that
Leopold will catch the mouse? If so, what should he do? 


Puzzle statistics "The mouse hunt".
Last updated 5332161.3 minutes ago.

Solved by: 11
Daily average: 0
Answers submitted: 18
Viewed by: 290
Fraction solved by: 3.7%
Solved at first attempt: 54.5%
Average discussion length: 2.2
Liked the puzzle: 5
Did not like the puzzle:
0

Tictactoe, the Megamind style 
Games puzzles 

Weight: 4 

Liked the puzzle: 100% 

26.02.2011 

Two Megaminds decided to play tictactoe using new rules. They use a
regular 3x3 playing pad, but each player can choose to
place either an X or an O into one of the cells. The winner is still
the one who arranges three X's or three O's in a line. Is there a
winning strategy in this game? Which player has it? 


Puzzle statistics "Tictactoe, the Megamind style".
Last updated 5332161.3 minutes ago.

Solved by: 7
Daily average: 0
Answers submitted: 8
Viewed by: 56
Fraction solved by: 12.5%
Solved at first attempt: 71.4%
Average discussion length: 1.4
Liked the puzzle: 2
Did not like the puzzle:
0



Once upon a time, a Megamind worked as an optometrist for an Occupier
who was color blind. The Occupier had a dream that he may regain
perfect vision if the Megamind made him a set of 9 red and 9 blue
crystals. The crystals should be of the same size,
but the blue ones should be heavier than the red ones. Crystals of the
same color should weigh the same. The Megamind completed the order and
brought two sets of crystals: blue in his right hand and red in the
left. The Occupier was suspicious, he did not trust the Megamind.
Fortunately, the Occupier has a balance scale. How can the Megamind
convince the Occupier that all crystals in one hand are blue and in
the other  red. He can use no more than three weighings. 


Puzzle statistics "18 crystals".
Last updated 5332161.3 minutes ago.

Solved by: 3
Daily average: 0
Answers submitted: 4
Viewed by: 295
Fraction solved by: 1%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 1
Did not like the puzzle:
0

The telephone cable 2 
Geometry puzzles 

Weight: 5 

Liked the puzzle: 100% 

01.01.2010 

The Megamind has a square parcel of land of size 1x1 km. Accidentally, he has found out that the devious Occupants had buried a telephone cable through his land and use it for their devious communications. The cable is buried along a straight line crossing the square land plot. After discovering this, the Megamind got his shovel and... paused to think. What is the shortest trench that the Megamind has to dig to find the cable? The trench may be disconnected. The proof of optimality is not required. 


Puzzle statistics "The telephone cable 2".
Last updated 5332161.3 minutes ago.

Solved by: 8
Daily average: 0
Answers submitted: 15
Viewed by: 295
Fraction solved by: 2.7%
Solved at first attempt: 75%
Average discussion length: 3.6
Liked the puzzle: 4
Did not like the puzzle:
0

Ladders with missing steps 
Logic puzzles 

Weight: 5 

Liked the puzzle: 100% 

17.01.2010 

To fix his roof, Megamind needs to climb up a ladder. He has found many ladders to choose from, but unfortunately some of them were missing steps. Megamind cannot climb a ladder if it is missing two or more steps in a row. Originally, all ladders had N steps, marked bottom to top. How many different ladders can Megamind climb? 


Puzzle statistics "Ladders with missing steps".
Last updated 5332161.3 minutes ago.

Solved by: 9
Daily average: 0
Answers submitted: 9
Viewed by: 284
Fraction solved by: 3.1%
Solved at first attempt: 77.7%
Average discussion length: 1.8
Liked the puzzle: 4
Did not like the puzzle:
0


