Brain Teasers 53 - Puzzle Prime

Out of Place

Section: Brain Teasers Category: Insight

Difficulty: Medium

Which of the numbers below is out of place and why?

1011, 2223, 3940, 5646, 8910

SOLUTION

Every number except 5646 can be split into a sequence of consecutive numbers: 1011~10-11, 2223~22-23, 3940~39-40, 8910~8-9-10.

Puzzle Prime July 13, 2017

2 Comments

Two Games at Once

Section: Brain Teasers Category: Insight

Difficulty: Medium

The Devil offers you a deal – you have to play two games of chess simultaneously against the two best GrandMasters in the world, one with black pieces and one with white pieces. If you win at least 1 point from the two games, you will get whatever your heart desires, if you don’t – you will go straight to Hell. Would you accept the challenge?

SOLUTION

Accept the challenge. You can easily get 1 point by just repeating the moves of your opponents. For example, if the white GrandMaster plays e4, then you play e4 against the black GrandMaster. If the back GrandMaster plays e5, then you play e5 against the white GrandMaster and so on.

Unknown Author July 7, 2017

2 Comments

Magic Liquid

Section: Brain Teasers Category: Insight

Difficulty: Hard

You buy a bottle with a letter from the merchant, the merchant tells you that when you drink the liquid in the bottle it grants you eternal life, he supposedly deciphered this from the letter.
After you get home you decide to study the letter if it really says what the merchant told you, can you figure out if the bottle really grants eternal life?

You come to a fork in the road.
To the left is an empty well made from stone.
On the right is a pirate’s buried treasure.
Ahead you only see a tall straight tree.
The night is dark with only a dying moon in the sky.

Source: Puzzling StackExchange

SOLUTION

The objects described in the last paragraph have the following shapes:
fork in the road = T
empty well = O
buried treasure = X
straight tree = I
dying moon = C
The 5 letters form the word “TOXIC”, which suggests you shouldn’t drink from the bottle.

Vajura July 1, 2017

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Bottle, Coin and Cork

Section: Brain Teasers Category: Insight

Difficulty: Easy

You put a little coin in an empty wine bottle and then insert the cork in its opening. How can you remove the coin without taking out the cork or breaking the bottle?

SOLUTION

Push the cork inside and then take out the coin.

Puzzle Prime June 28, 2017

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Camel in the Desert

Section: Brain Teasers Category: Insight

Difficulty: Advanced

One man is trying to cross the desert to reach the neighboring village. It takes 4 days to get there, but his camel can carry bananas which will feed him for 3 days only. How can the man reach the neighboring village without starving?

SOLUTION

The man travels one day, leaves one portion of bananas in the desert and returns back to his village. Then he leaves again with 3 new portions of bananas, picks the portion left in the desert on his way and ends up in the neighboring village on the sixth day.

Unknown Author June 19, 2017

5 Comments

Basket with Apples

Section: Brain Teasers Category: Lateral

Difficulty: Easy

A mother was carrying a basket with 4 apples inside. She went to her 4 children and gave each of them an apple. Yet, there was still one apple left in the basket. How come?

SOLUTION

The mother gave one of the children the basket with one of the apples inside.

Puzzle Prime June 16, 2017

0 Comments

Birthday Candles

Section: Brain Teasers Category: Insight

Difficulty: Easy

If 10 Birthday candles burn out in 8 minutes, in how many minutes will 15 Birthday candles burn out?

SOLUTION

Every candle burns out in 8 minutes, so the answer is 8.

Unknown Author June 13, 2017

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15 Puzzle

Section: Brain Teasers Category: Mathematics

Difficulty: Expert

On the picture, you can see the famous “15 Puzzle”. The rules are simple – you can slide any of the 15 squares to the empty spot if it neighbors with it. The question is: if the squares with numbers 14 and 15 are exchanged, can you solve the puzzle, i.e. can you bring it to the state shown on the picture?

SOLUTION

No, you can’t. In order to see this, at each moment count the number of pairs of little squares, which are wrongly ordered. For example, if the numbers on the first row are 7, 2, 12 and 5 in this order, then 7 and 2, 7 and 5, and 12 and 5 are wrongly ordered. Notice that after every move you make, the number of wrongly ordered pairs changes with an odd number – ± 3 or ± 1. If you want to go from the state in which squares 14 and 15 are exchanged to the solved state on the picture, you must make an even number of moves and therefore you would change the number wrongly ordered pairs by an even number. However, the number of wrongly ordered squares in the starting state is 1, whereas in the ending state is 0, which yields a contradiction.

Unknown Author June 10, 2017

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