
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 





A Megamind owns a mint with a 100 workers. Each day, he gives 1kg of
gold to each worker, and each worker must make 100 coins (10 grams
each). The Megamind learnt that one nof the workers is a forger, he
makes coins that are 1g lighter. How can Megamind determine the forger
using only one weighing? The scales can determine the total weight, up
to 100 kg. 


Puzzle statistics "A forger".
Last updated 6879028.6 minutes ago.

Solved by: 31
Daily average: 0
Answers submitted: 31
Viewed by: 296
Fraction solved by: 10.4%
Solved at first attempt: 96.7%
Average discussion length: 1.0
Liked the puzzle: 7
Did not like the puzzle:
1


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 6879028.6 minutes ago.

Solved by: 48
Daily average: 0
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


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 6879028.6 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


A Megamind was doing his laundry. The washer's manual says that a
standard load of detergent is 220 g. The Megamind has
a bag of dry detergent containing exactly 1 kg, the balance scale, and
four weights: 2x10 g and 2x5 g. How can the Megamind
obtain exactly 220 grams of detergent using at most three weighings? 


Puzzle statistics "Laundry".
Last updated 6879028.6 minutes ago.

Solved by: 1
Daily average: 0
Answers submitted: 1
Viewed by: 1
Fraction solved by: 100%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 5
Did not like the puzzle:
1


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? 


Puzzle statistics "101 coins".
Last updated 6879028.6 minutes ago.

Solved by: 15
Daily average: 0
Answers submitted: 16
Viewed by: 293
Fraction solved by: 5.1%
Solved at first attempt: 100%
Average discussion length: 1.0
Liked the puzzle: 4
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 6879028.6 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


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? 


Puzzle statistics "12 coins".
Last updated 6879028.6 minutes ago.

Solved by: 10
Daily average: 0
Answers submitted: 10
Viewed by: 273
Fraction solved by: 3.6%
Solved at first attempt: 80%
Average discussion length: 1.4
Liked the puzzle: 4
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 6879028.6 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


There are six weights 1,2,3,4,5,6 grams. They are labeled with numbers
1,2,3,4,5,6. Some may be mislabeled. How can you determine whether all
labels are correct using a balance scale? What is the minimal number
of weighings? 


Puzzle statistics "Correct labels".
Last updated 6879028.6 minutes ago.

Solved by: 6
Daily average: 0
Answers submitted: 6
Viewed by: 291
Fraction solved by: 2%
Solved at first attempt: 83.3%
Average discussion length: 2.0
Liked the puzzle: 4
Did not like the puzzle:
0


