A town was invaded by aliens, and some of its residents were kidnapped and replaced by shapeshifters. You're tasked with capturing one of the shapeshifters. Here's the setup: There are 7 residents of the town. At least 4 of the residents are humans, and the remainder are shapeshifters. Everyone ...

You are playing a snake game. The snake starts in the top-left corner of a grid. Each cell of the grid is either empty or a wall. Each turn you can press a key to move the snake in one of four directions: either horizontally or vertically. Once a key is pressed, the snake moves in the assigned di...

I sent six puzzles to the Times but received the following reply: Dear Sir, We are sorry to reject your crossword submissions for the following reasons: Squares must be 15x15 or 21x21 Words cannot be duplicated Nonsense words are undesirable Sincerely, The Editor I was going to try the Sun in...

You are playing a snake game. The snake starts in the top-left corner of a grid. Each cell of the grid is either empty or a wall. Each turn you can press a key to move the snake in one of four directions: either horizontally or vertically. Once a key is pressed, the snake moves in the assigned di...

In a colony, there are men, women, and children. 4 women can carry as much water as 7 children. 3 men can carry as much water as 2 women and 1 child combined. If 7 men, 15 women, and 4 children each visit 36 journeys to bring 1l of water, then how many journeys would 14 men, 12 women, and 21 chil...

Looking at David Ahl's Basic Computer Games, one of the programs that caught my eye was One Check. It's like Peg Solitaire, which I've figured, but it's on an 8x8 board with the 4x4 inner bit hollowed out. I am wondering how to leave just one peg on the board. 01234567 0 xxxxxxxx 1 xxxxxxxx 2 x...

Ana and Bob are writing symbol $X$ alternatively on board $2022\times 1$. Winner is the one who makes 3 consecutive $X$. Who has wining strategy if Ana starts? Describe it.

What is the code in: eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeooeeeeeeeeeeeeeppeeeeeiiiieeeeeooeeeeeeeeeeppppppppeeiiiieeeeeooeeooooeeeeeeeppeeeeeeeeeeeeooooeeeeooooeeeppeeeeeiiiieeeeeooeebbbbbbboobbbbbbeeiiiieeeeeooeebbeeeeeooeeppeeeeeiiiieeeeeooeebbbbbbbbbbbppbbeeiiiieeeeeoooobbbbbbbbbbbppbbeeiiii...

In the kingdom of underwaters, there was a game that all the nymphs liked to play. In four chests, four different coins gold, Silver, Copper and Bronze were kept in the underwater fountains. One day, 123 nymphs came to play 'Guess what's in which box?' While all the 123 nymphs were done guessing,...

This is a puzzle from the Expert section of my game Fetching Alchemist, visually modified for presentation here. It is a variant of the Travelling Salesman problem where you are trying to complete a set of quests. The red numbers indicate the distance of each road. You need to find the shortest ...

In a Colony, there are men, women and children. 4 women can carry as much as water as 7 children. 3 men can carry as much as 2 women and 1 child combined. If 7 men, 15 women and 4 children each visit 36 journeys to bring 1L water, then how many journeys would 14 men , 12 women and 21 children ne...

What begins with letter T and ends with letter T, use after

17 identical coins with diameter 1 are lying flat on a table, such that their midpoints build the vertices of a regular 17-gon (regular heptadecagon) and adjacent coins touch each other. What is the maximum number of coins, which can be added inside the 17-gon, none of them overlap and lying flat...

$$ {2\over x-14}+ {5\over x-11} = {5\over x-13}+ {2\over x-9}$$ It is puzzling me for a days. I'm getting huge polynomial I don't like.

We have a paralelogram $ABCD$ and point $P$ inside it. Halflines $BP$ and $DP$ cuts respectively lines $AD$ and $AB$ at $E$ and $F$. Why are the area of $ABPD$ and $CEPF$ the same regardles of the position of $P$?

Squares $ABCD, DCGH, BEFG$ and $ELKM$ are positioned as shown on the picture. Find the area of triangle $DGK$ if you know that the area of square $ABCD$ is $20$.

This is a puzzle from the Expert section of my game Fetching Alchemist, visually modified for presentation here. It is a variant of the Travelling Salesman problem where you are trying to complete a set of quests. The red numbers indicate the distance of each road. You need to find the shortest ...

This is the third maze in the Wormeus series. Previous puzzles are here and here This shouldn’t be too difficult but contains a cute gimmick that isn’t possible in the original Theseus mazes sans the requirement of eating all the apples. Here is a quick recap of the rules: Wormeus’s actions are...