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| 1. |
markr |
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100 |
| 2. |
monkeyspike |
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28 |
| 3. |
Pai, Srikanta |
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25 |
| 4. |
M_87 |
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24 |
| 5. |
mgritter |
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17 |
| 6. |
mathislife22 |
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13 |
| 7. |
lessthanepsilon |
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12 |
| 8. |
Azrail |
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9 |
| 9. |
Muni |
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8 |
| 10. |
JK |
- |
7 |
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| 1. |
alan |
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176 |
| 2. |
denisR |
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167 |
| 3. |
idler_ |
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104 |
| 4. |
tolstyi |
- |
55 |
| 5. |
vale |
- |
32 |
| 6. |
STARuK |
- |
9 |
| 7. |
Mosk |
- |
2 |
| 8. |
Black, kshor, Mouse, sergeip, xandr |
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0 |
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There is true expression on panel. But only one pixel is defective. Which one?
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Puzzle statistics "Defective pixel".
Last updated 67132.1 minutes ago.
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Solved by: 14
Daily average: 0.21
Answers submitted: 15
Viewed by: 25
Fraction solved by: 56%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 7
Did not like the puzzle:
0
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| 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? |
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Puzzle statistics "8 coins".
Last updated 67132.1 minutes ago.
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Solved by: 12
Daily average: 0.17
Answers submitted: 13
Viewed by: 26
Fraction solved by: 46.1%
Solved at first attempt: 91.6%
Average discussion length: 1.2
Liked the puzzle: 4
Did not like the puzzle:
0
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| A Megamind walked along a fence and discovered strange pairs of
numbers. First, he saw "188->4". A bit fаrther, he discovered
"232->0". A few steps after that, "100->2". Then, "163->1". Then he
saw a little boy who was just beginning to paint something. When the
Megamind called a boy, he ran away. Approaching the site, the Megamind
saw an incomplete pair "386->...". He took out his favorite marker and
completed the pair. What number did he write? |
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Puzzle statistics "Numbers on the fence".
Last updated 67132.1 minutes ago.
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Solved by: 8
Daily average: 0.11
Answers submitted: 8
Viewed by: 26
Fraction solved by: 30.7%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 3
Did not like the puzzle:
0
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| 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. |
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Puzzle statistics "Obtain 24".
Last updated 67132.1 minutes ago.
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Solved by: 14
Daily average: 0.19
Answers submitted: 14
Viewed by: 27
Fraction solved by: 51.8%
Solved at first attempt: 92.8%
Average discussion length: 1.1
Liked the puzzle: 5
Did not like the puzzle:
0
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| 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. |
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Puzzle statistics "The fifth number".
Last updated 67132.1 minutes ago.
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Solved by: 10
Daily average: 0.16
Answers submitted: 10
Viewed by: 21
Fraction solved by: 47.6%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 6
Did not like the puzzle:
0
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| 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? |
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Puzzle statistics "101 coins".
Last updated 67132.1 minutes ago.
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Solved by: 6
Daily average: 0.09
Answers submitted: 6
Viewed by: 24
Fraction solved by: 25%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 2
Did not like the puzzle:
0
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| 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 truth-teller. 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? |
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Puzzle statistics "A circle of lies".
Last updated 67132.1 minutes ago.
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Solved by: 3
Daily average: 0.05
Answers submitted: 3
Viewed by: 14
Fraction solved by: 21.4%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 2
Did not like the puzzle:
0
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| The mouse hunt |
Games puzzles |
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Weight: 4 |
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Liked the puzzle: 100% |
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11.01.2010 |
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| 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? |
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Puzzle statistics "The mouse hunt".
Last updated 67132.1 minutes ago.
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Solved by: 3
Daily average: 0.05
Answers submitted: 4
Viewed by: 20
Fraction solved by: 15%
Solved at first attempt: 66.6%
Average discussion length: 1.3
Liked the puzzle: 2
Did not like the puzzle:
0
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| Ladders with missing steps |
Logic puzzles |
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Weight: 5 |
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Liked the puzzle: 100% |
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17.01.2010 |
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| 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? |
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Puzzle statistics "Ladders with missing steps".
Last updated 67132.1 minutes ago.
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Solved by: 3
Daily average: 0.05
Answers submitted: 3
Viewed by: 14
Fraction solved by: 21.4%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 2
Did not like the puzzle:
0
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| A game with wooden sticks |
Games puzzles |
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Weight: 5 |
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Liked the puzzle: 100% |
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02.01.2010 |
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| 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)? |
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Puzzle statistics "A game with wooden sticks".
Last updated 67132.1 minutes ago.
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Solved by: 2
Daily average: 0.02
Answers submitted: 3
Viewed by: 26
Fraction solved by: 7.6%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 1
Did not like the puzzle:
0
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