Hard – Page 11 – Puzzle Prime

Rubik’s Chess

Section: Brain Teasers Category: Deduction

Difficulty: Hard

Last week we found out that Puzzle Pranks Co. have invented a new type of puzzle – Rubik’s Chess. The goal is simple – you get a scrambled cube with various chess pieces on its sides, and you must unscramble it so that on each side there is one mated King, assuming the kings cannot capture the neighboring pieces (Queens, Rooks, Bishops, kNights).

We are usually good with this type of puzzles, but we spent our entire weekend trying to solve this one without any success. We even started wondering if it can be actually solved, so decided to share it with you and see if you can help us figure that out.

Below you can see the way the cube looks when seen from 8 different angles:

Remark: The orientations of the pieces are irrelevant to the final solution, i.e. they don’t need to be consistent on each side.

SOLUTION

The Rubik’s Chess puzzle cannot be solved. You can see a detailed solution HERE.

Puzzle Prime November 1, 2017

0 Comments

Queen’s Death

Section: Brain Teasers Category: Chess

Difficulty: Hard

On which spot was the white queen captured?

SOLUTION

Since the pawns on e6 and h6 have taken 2 of the White’s pieces, and the only two white pieces which could get there are the knight and the queen, the answer is one of these two squares. Similarly, the pawn on b3 should have taken the Black’s c8 bishop, and this should have happened before the White’s queen was taken. Therefore first the white knight was taken on e6, then the black bishop on b3, and finally the white queen on h6.

Raymond Smullyan September 28, 2017

0 Comments

Deadly Vodka

Section: Brain Teasers Category: Lateral

Difficulty: Hard

Two politicians go to a bar and order two glasses of vodka on the rocks. The first politician quickly empties his glass, then orders a second one, a third one… The second politician patiently drinks his own vodka, but about 20 minutes later, he drops down dead. The police discovered that the barman tried to assassinate both politicians, but how come the second one died and the first one lived?

SOLUTION

The poison was in the ice cubes, so the second politician drank them when they melted in his drink.

Unknown Author September 13, 2017

0 Comments

Breakfast with Friends

Section: Casual Puzzles Category: Riddle

Difficulty: Hard

One early morning, a group of friends meets in their favorite café.

Ash, the biggest in the group, remarked :

“Must have been millions of years since we were all together, uh?”

Affie, who was wearing her brand new elephant pants, nodded. Anthony kept on complaining about the weather back home.

“Yeah, I am glad to be here with you, it is so cold at my place!”

Eugenie, who was saddened by the loss of a friend, was looking at Samuel and Namur, who were arguing about the possible future election of Donald Trump.

“These two are really inseparable”, she said to herself.

Octavia, the smallest among her friends, stood and spoke :

“Guys, I have a surprise for you! We’re going to the opera tonight!”

The waiter, waiting for the orders, wondered why these customers reminded him of something. But all of a sudden, he said:

“Ladies and gentlemen, may I suggest some sliced bread with butter, slices of cheese and ham? We also have croissants and other pastries. And for drinking, is coffee fine? We also have tea, of course, and orange and apple juice for you.”

Which is this group of friends, and what came to the waiter’s mind?

SOLUTION

These are the seven continents – Ash (Asia), Affie (Africa), Anthony (Antarctica), Eugenie (Europe), Samuel (South America), Namur (North America), Octavia (Oceania). Their entire conversation consists of various hints. In the end, the waiter was thinking about bringing them Continental Breakfast.

Source:

Puzzling StackExchange

IAmInPLS August 13, 2017

3 Comments

Cork in a Glass

Section: Brain Teasers Category: Science

Difficulty: Hard

You have a jar filled with water and a glass. If you pour some water into the glass and place a cork in it, the cork will float towards the edges of the glass. What is the easiest way to make the cork float towards the center?

SOLUTION

Since the liquid molecules adhere to the glass molecules on the sides of the glass, the water level there is higher and buoyancy makes the cork float in that direction. If you fill the glass all the way to the edge, then the water surface will be convex and the cork will float towards the center.

Unknown Author August 7, 2017

0 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

0 Comments

Move a Card

Section: Brain Teasers Category: Insight

Difficulty: Hard

Can you move just one card so that you get a correct identity?

SOLUTION

Yes, you can, as shown below.

Unknown Author May 28, 2017

1 Comment

Chessboard Infection

Section: Brain Teasers Category: Mathematics

Difficulty: Hard

On a standard 8×8 chessboard there are 7 infected cells. Every minute each cell which has at least 2 infected neighbors gets infected as well. Is it possible for the entire chessboard to get infected eventually?

SOLUTION

The total perimeter of the infected regions never increases. If there are 7 infected cells initially, their total perimeter is at most 28. The perimeter of an 8×8 square is 32. Therefore, it is impossible to infect the entire chessboard.

Unknown Author May 4, 2017

2 Comments

Pirate’s Treasure

Section: Brain Teasers Category: Deduction

Difficulty: Hard

Five pirates steal a treasure which contains 100 gold coins. The rules for splitting the treasure among the pirates are the following:

The oldest pirate proposes how to split the money.
Everybody votes, including the proposer.
If there are more than 50% negative votes, the proposer gets thrown in the water and the procedure repeats.

Given that the pirates are very smart and bloodthirsty (if they can kill another without losing money, they will do it), how should the oldest pirate suggest to split the money among the five of the in order to maximize his profit?

SOLUTION

Solve the problem backward. Let the pirates be called A, B, C, D, E, where A is older than B, B is older than C, C is older than D and D is older than E.
If there are only two pirates left – D and E, then the D will keep all the treasure for himself.
If there are three pirates left – C, D, and E, C can propose to give just 1 coin to E and keep the rest for himself. Pirate E will agree because otherwise, he will get nothing.
If there are four pirates left – B, C, D, and E, then B can propose to give just 1 coin to D and keep the rest for himself. Pirate D will agree because otherwise, he will get nothing.
Now if there are five pirates – A, B, C, D and E, A should give coins to at least two other pirates, because otherwise at least three of them will vote negative. Clearly, B will always vote negative, unless he gets offered 100 coins and D will also vote negative, unless he gets 2 coins or more. Pirate A can offer to give one 1 coin to C, 1 coin to E and keep the rest for himself and this is the only optimal proposal – 98:0:1:0:1.

Unknown Author April 16, 2017

0 Comments

A Maze Puzzle for the Day

Section: Brain Teasers Category: Insight

Difficulty: Hard

Here’s a little maze puzzle I originally built a couple of years ago, that seems apropos to reprise now:

Can you make it from the A in the top left of this grid to the Z in the bottom right, always going either up one letter (for instance, A to B or G to H) or down one letter (for instance, N to M)? The alphabet wraps around, so you can go from Z up to A or A down to Z too. Try as hard as you can (and remember that you can always work backward if you get stuck forwards), and see where you get!

Remark: Solving the maze is not the same thing as solving the puzzle. Read those instructions carefully!

SOLUTION

Notice this puzzle is published on April 1st. Actually, it doesn’t have a standard solution. If you connect every two consecutive letters which appear next to each other in the grid, you will get two disconnected components, one of which contains the START and the other contains the END. The first component has 5 dead-ends – at letters A, P, R, I, L, and the second component has 5 dead-ends – at letters F, O, O, L, S. These two spell out “April Fools”, which is the real solution of the maze.

Steven Stadnicki April 1, 2017

0 Comments