Practical - Puzzle Prime

Fold Into a Cube

Section: Brain Teasers Category: Practical

Difficulty: Advanced

Cut out the black shape and then fold it perfectly into a cube, without overlapping.

SOLUTION

If the size of each of the small edges of the shape is equal to 1cm, then its area is equal to 30cm². Thus, the cube that is formed by the shape must have an edge of length √5cm. If we set the center of the black shape to be the center of one of the cube’s faces, then the four closest vertices must lie on the boundary of the shape, √2.5cm away. This determines uniquely the folding of the shape which is shown on the simulation below.

Source:

Puzzling Stackexchange

plasticinsect March 13, 2024

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The Letter E

Section: Brain Teasers Category: Practical

Difficulty: Expert

Click the image to enlarge it and download it. Then print it, cut out the three pieces, and rearrange them so that you get the letter “E”.

SOLUTION

Rearrange the pieces, so that they form the shadow of the letter “E”, as shown below.

Unknown Author February 10, 2024

1 Comment

Touch or Don’t Touch

Section: Brain Teasers Category: Practical

Difficulty: Hard

For this puzzle/game, you need to keep presenting various words to your friends and telling them whether they are “TOUCH” or they are “DON’T TOUCH”. Below, we have listed several words from each category.

TOUCH: banana, proof, mouse, keyboard, promo, woman

DON’T TOUCH: cherry, solution, cat, screen, discount, girl

Can you guess what determines whether a word is “TOUCH” or “DON’T TOUCH”?

SOLUTION

Words that make your lips touch when pronounced belong to the “TOUCH” category, while the others belong to the “DON’T TOUCH” category. The sounds “P”, “B”, “M”, and “W” that cause this are called “bilabial”.

Unknown Author September 1, 2023

3 Comments

We Go on Vacation

Section: Brain Teasers Category: Practical

Difficulty: Advanced

For this puzzle/game, you will need to find a group of friends, preferably 5 or more. The premise is that you will go together on a vacation but each of you can bring only specific items there. The rules regarding which items can be brought and which not are known by one of the players and the other ones are trying to guess them.

In the exchange below, George is the one organizing the trip and the one who knows which items the rest are allowed to bring.

GEORGE: I will take my guitar with me. What do you want to take?

SAM: Can I take an umbrella with me?

GEORGE: No, you cannot take an umbrella, but you can take some sunscreen.

HELLEN: Can I take a scarf with me?

GEORGE: No, you cannot take a scarf, but you can take a hat.

MONICA: Can I take a dress with me?

GEORGE: No, you cannot take a dress, but you can take some makeup.

Can you guess what the rules of the game are?

SOLUTION

Everyone is allowed to take with themselves only items whose first letter is the same as the first letter of their names. Thus, George can take a Guitar, Sam can take Sunscreen, Hellen can take a Hat, and Monica can take Makeup.

Unknown Author December 22, 2022

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Pronunciation Puzzles

Section: Brain Teasers Category: Practical

Difficulty: Medium

The following 2 puzzles rely on misleading phrasing of the questions. Read them aloud to your friends and let them ponder upon them.

What has 4 letters, sometimes 9, and never 5
One night a king and a queen stayed in a hotel. On the next day, three people checked out. Who was the third person?
There are 30 cows and 28 chickens. How many didn’t?
Pronounce the following words: T-W-A, T-W-E, T-W-I, T-W-O
As I was walking across the London Bridge, I met a man.
He tipped his hat, and drew his cane.
In this riddle, I said his name. What is it?

SOLUTION

The first puzzle is not a question. It is a statement, saying that the word “what” has 4 letters, the word “sometimes” has 9 letters, and the word “never” has 5 letters. There is nothing to solve, so the puzzle is figuring that out!

The second puzzle reads as “One knight, a king, and a queen stayed in a hotel.” Thus, the third person was the knight.

The third puzzle reads as “There are 30 cows and 20 ate chickens. How many didn’t?” Thus, the answer is that 10 cows didn’t eat chickens.

The fourth question often confuses people and they pronounce TWO as [twou] instead of [tuː].

The fifth riddle actually says: “He tipped his hat, ‘Andrew Hiscane'”. Thus, the name of the man is Andrew Hiscane.

Unknown Author August 4, 2021

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FEATURED

Square Impossible

Section: Brain Teasers Category: Practical

Difficulty: Advanced Tags: Featured

Take a square (or circle) coaster. Then, cut a hole in a piece of paper with the shape of a square, so that the side of that square is half of the side (or the diameter) of the coaster. Now, your goal is to push the coaster through the hole without tearing the paper (you can fold it).

SOLUTION

Coming soon.

Unknown Author July 13, 2021

3 Comments

FEATURED

Cut and Arrange

Section: Brain Teasers Category: Practical

Difficulty: Hard Tags: Featured

Get a piece of paper with dimensions 9×12 with a 1×8 rectangular hole in the middle. Then, cut the paper into two pieces that can be arranged into a square. You can print out the shape below.

SOLUTION

The solution is shown below.

Unknown Author May 13, 2021

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Petals Around the Rose

Section: Brain Teasers Category: Practical

Difficulty: Medium

This is a puzzle that is best played with friends and real dice on a table. The rules require one of the players to throw 5 dice at once, and then answer correctly “how many petals there are around the rose”. The procedure gets repeated until everyone has discovered the secret rules of the puzzle or has given up.

How many throws do you need in order to figure out this classic puzzle?

There are 6 petals around the rose.

SOLUTION

The roses are the middle dots on the dice, and the petals are the dots around them. Just count the number of all petals appearing on the five dice and you will get the answer. 1 -> 0, 2 -> 0, 3 -> 2, 4 -> 0, 5 - > 4, 6 -> 0.

Unknown Author December 3, 2020

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Fascinating Dissection

Section: Brain Teasers Category: Practical

Difficulty: Medium

First, print and cut the pieces below. Then, arrange them so that they form a triangle and then rearrange them so that they form a square.

SOLUTION

The solution is shown below.

What is fascinating about these dissections is that one can transform into the other by keeping the pieces attached to each other in a chain and simply rotating them around the hinge points.