Most Popular

1500 questions
54
votes
1 answer

re-re-reCAPTCHA

Last Friday, I was feeling a bit sad because I hadn't earned much rep recently, so I decided to try this awesome sock puppet thing everyone's been raving about. I logged out of my normal Puzzling account, and started to create a new account. I…
Dan Russell
  • 16,028
  • 3
  • 45
  • 97
54
votes
3 answers

A new way to cut a pizza

Can you cut a pizza (circle) into 12 congruent pieces, such that half of them have crust (circle boundary), while the other half do not? The pieces must have the same shape and area, but can be mirrors of each other. Bonus: Can you do it with…
Dmitry Kamenetsky
  • 35,897
  • 5
  • 66
  • 276
54
votes
3 answers

The Case of the Miscalculating Calculator

At the Arithmetic Company, to try and cut down labor costs the administration commissioned a calculator to be made. The calculator was produced, and in the quality control division was tested with the following values: 20 + 3 = 23 5 + 15 = 20 7 + 9…
KSab
  • 1,142
  • 9
  • 15
53
votes
1 answer

A Puzzle That Asks Why There's A Dryer in my Search Engine

The bag is not transmogrified. A hookah with some fizz inside. The snake, the bite. The words of pride.
Hugh Meyers
  • 23,712
  • 1
  • 52
  • 171
53
votes
5 answers

I have three siblings, but some would say four

I have three siblings, but some would say four. They say we are all, from the sky to the floor. My brothers formed a band, but I wasn't invited. Without me, you and the reaper will soon be united. Who or what am I?
qwertyu63
  • 3,919
  • 19
  • 45
53
votes
4 answers

This is not a spam post

Smart enough to solve this puzzle? Practised in the art of counting in multiple ways? VACANCIES OPEN! PM me to learn more about fantastic employment opportunities for talented puzzlers such as yourself. Don't pass up this chance for an amazing…
Rand al'Thor
  • 116,845
  • 28
  • 322
  • 627
53
votes
2 answers

A Robot's Last Words

There, spread out all over the floor, were the mechanical pieces of a robot. Something had torn it apart, and the debris spanned a radius of a few meters. There was no sign of what might have caused this tragedy. What monster, what disaster, could…
Tryth
  • 13,960
  • 5
  • 39
  • 81
53
votes
3 answers

You're not feeling well. You need something.

You're not feeling good. Something is horribly wrong with you. You're trying hard to feign happiness, but... ...deep inside, you feel dead. ...deep inside, you are hurt. ...deep inside, you know you are hated. ...deep inside, you are all…
Ankoganit
  • 18,612
  • 3
  • 74
  • 133
53
votes
3 answers

Sliding Bolt Puzzle

You are in a room with two adjacent doors locked by four sliding bolts. The bolts are movable and block only one door at a time; however, you do not know which bolt currently is blocking which door. An example configuration: Luckily, there are…
diabonas
  • 968
  • 8
  • 16
53
votes
1 answer

What is Lukas Rotter's secret?

The former user Lukas Rotter has had1 an intriguing profile picture: This looks like it's some kind of encrypted message! And just to confirm my suspicions, on his profile he says: By the way, my profile picture is also a little puzzle. You'll get…
Rand al'Thor
  • 116,845
  • 28
  • 322
  • 627
53
votes
4 answers

Is this chromatic puzzle always solvable?

I've created a new puzzle from an Alexey Nigin's idea. It consists of a 8x8 board where each square is randomly assigned one of three colors. A movement is defined by picking any two orthogonal adjacent squares (forming a domino shape) with…
Edgar G.
  • 1,003
  • 9
  • 16
53
votes
1 answer

''If the B...''

This is an ancient puzzle from an old book that I've never seen anywhere else. Can any of you puzzlers solve it? If the B MT put: If the B. putting:
JimBobOH
  • 783
  • 5
  • 10
53
votes
1 answer

Mathematical Rebus

Mathematical Rebus II Mathematical Rebus III $$ 4\sum_{n=0}^{\infty}\frac{(-1)^n}{2n+1}\\ (-\infty,...,-1,0,1,...,\infty)\times(-\infty,...,-1,0,1,...,\infty)\\ \forall\begin{bmatrix}{-1}&{0}\\ {0}&{-1} \end{bmatrix} $$
Masclins
  • 2,726
  • 18
  • 39
52
votes
5 answers

There are 2,001 doors leading to 2,001 hallways. How quickly can you find the way out?

Once again, you have angered the Emperor, and she has imprisoned you in a special prison. “I do have a bit of good news for you,” the Emperor has told you. “You're only two doors away from freedom, and I've left all the doors unlocked for you!” Of…
Tanner Swett
  • 2,319
  • 14
  • 23
52
votes
5 answers

Prime Number Snake

Place numbers 1 to 100 in the cells of the 10 x 10 board below in such a way that consecutive numbers occupy neighboring cells (either horizontally or vertically). Shaded cells should contain only prime numbers.
Bernardo Recamán Santos
  • 18,674
  • 2
  • 37
  • 218