Questions tagged [strategy]

A puzzle whose solution is a methodological plan of action for realizing a specific goal.

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1
vote
3answers
177 views

Clearing the Snakes

While space was being cleared for a new building, a bunch of scitales came out of the water to munch on the worker's lunches, before falling asleep in the way of everything. You, having a knack for ...
4
votes
1answer
156 views

Can you destroy the kingdom without getting caught?

You are a shapeshifter that takes on the form of their victims and you've infiltrated the opposing kingdom's ranks, disguised as a lowly pawn . The opposing king has you presently assigned to the ...
9
votes
1answer
940 views

Strategies for Circuit Board Puzzle from NYT

The New York Times publishes a collection of variety puzzles each week, and new to the rotation recently is one called "Circuit Board". Here is an example of a puzzle (I added coordinates ...
0
votes
1answer
115 views

Catching the Vegetable-Goose [closed]

After an altercation involving giant bees, you have been sentence to some hard labour, specifically harvesting barnacle-lambs: a gourd-like fruit that grows geese in its shell While working, you get ...
13
votes
7answers
2k views

Spiders on a cube

Two spiders are trying to catch an ant. All are constrained to move along the edges of a transparent cube. The speed of the ant is $1$. The speeds of the spiders are $v_1$ and $v_2$ respectively. What'...
11
votes
1answer
431 views

How long can you survive at the devil's playground?

The devil has trapped you in his playground. The devil knows that you can't cross over the burning boundary of his circle, so he allows you to choose a position within the circle before he starts to ...
0
votes
4answers
463 views

Secretly press different buttons

Consider a game played with 12 people. 9 are randomly assigned to Team Good and 3 to Team Evil. Players on Team Evil know their teammates, but players on Team Good don't. Two of the players on Team ...
1
vote
1answer
201 views

Optimal parking at a concert

You are going to a concert. The road to the concert has 100 car parking spaces arranged in a straight line. The spaces are numbered from 1 to 100, where space 1 is in the beginning of your journey and ...
2
votes
1answer
117 views

How to achieve a yellow cross on Rubik's cube from three yellow edges on the top layer?

I have finished the first and middle layers on a Rubik's cube and now I would like to complete the yellow cross on the third layer. Every instructions manual I have seen assures that there are one of ...
17
votes
3answers
874 views

Reunite the Stars

On an infinite plane, the Prime Star has disintegrated into four constituent stars, the North Star, the South Star, the East Star and the West Star, each traveling at a constant speed of 1 in their ...
7
votes
0answers
236 views

A Glutton and a Split Check

N, T, A, B are arbitrary constants in this problem. I have only definitively solved the N=1 subproblem, so, if the general problem cannot be solved, I will be satisfied to mark as accepted a solution ...
4
votes
2answers
441 views

Sorting kids by hat colours [duplicate]

I have taken a group of students on a school trip. I want to organise them into two groups and so I have given each one a coloured hat. Some hats are red, while others are blue. Each child can see ...
5
votes
2answers
261 views

Five friends and two motorcyclists

Five friends Alice, Bob, Carole, Dylan and Emma are heading to a common destination 100 unit distance away. They start together. Grandma Alice walks at a speed of 1. Bob and Carole walk at speeds 4 ...
18
votes
4answers
6k views

√2 without pressing √ on a Scientific Calculator

You have to calculate $\sqrt{2}$ on your scientific calculator by only pressing these buttons: ...
3
votes
1answer
204 views

Nanobots Algorithm

Four tiny robots or Nanobots with dimensions 1 x 2 nm are on their initial 2 by 2 state. They shall be transform to phases I , II & III subsequently for specific tasks (see figures). Each nanobots ...
6
votes
1answer
385 views

The Novice Chess Team that Won Every Match of the Season

Devious High School had a newly formed chess team that played against all the other high schools in the area this year. These matches are played with a 5-player team who, at a match, sit next to each ...
6
votes
2answers
480 views

The Blindfold CASIO fx-570EX Puzzle

You and your friend are playing a game with the CASIO fx-570EX calculator. The game proceeds as follows: Your friend types a number, then presses a left parenthesis, and then types another number(e.g....
1
vote
2answers
260 views

Elementals and Aliens

Rules/Story You have been kidnapped and locked in the maze under the bathhouse you work at by 5 aliens: a Mercurian, Venusian, Martian, Jovian, and Saturnian. Currently, the aliens are spread ...
4
votes
1answer
196 views

Mastermind: What should I guess next? That depends

Bob was playing a popular adventure game on his computer, and he came across a Mastermind minigame. Here's the results of his first four guesses: Bob has never been great at solving logic puzzles on ...
2
votes
0answers
116 views

General Approach to Solving Cryptarithms

I have recently started honing my problem-solving skills, starting with number-related puzzles. Cryptarithms have appeared frequently, so I was wondering whether there is some sort of general approach ...
10
votes
2answers
447 views

Transform a pile of cards in reverse order

There are 52 cards on a table and numbered in order from 1 to 52 with number 1 on top. The following operation can be repeatedly done: split the pile into two piles without shuffling and take cards ...
11
votes
2answers
613 views

Two dimensional Mastermind

You have probably played the classic game of Mastermind with 4 pegs and 6 colours. It turns out that the codebreaker can always find the pattern in 5 moves or fewer. Now consider the 2D version of the ...
5
votes
3answers
432 views

100 prisoners and a secret number (sequel)

Inspired by this brilliant puzzle by @DmitryKamenetsky! Much to the annoyance of the guards, the sly prisoners bribed a guard and learnt about the number in the envelope in advance, and the first ...
32
votes
9answers
3k views

100 prisoners and a secret number

There are 100 prisoners numbered from 1 to 100. They know their own numbers. There is an interrogation room with a table and an envelope. The envelope contains a secret number - an integer chosen ...
6
votes
2answers
423 views

A three-way bet

Alice, Bob and Carole are playing a betting game. At the beginning, they have 20 chips in the common pot. They move alternatively in the order of Alice, Bob and Carole. In their move, a player ...
12
votes
1answer
351 views

How should you bet?

Alice and Bob are playing a betting game. Each has 20 chips to start with. They move alternatively starting with Alice. In their moves, they name a number $n$ and toss a fair coin: if head, they get $...
3
votes
3answers
333 views

How many pilots do they need?

I have just watched this old riddle video from Ted-Ed. It basically asks how can three pilots coordinate their flights such that the professor (one of the three pilots) can circumnavigate the earth. I ...
9
votes
1answer
278 views

Survive the infinite zombie attack II

Zombies are back again. Same as last time, You're at the origin, and zombies occupy the points $(100𝑖,100𝑗)$ for all integers $𝑖,𝑗$ except the origin, as shown below: The ratio of your speed to ...
5
votes
2answers
302 views

Even and odd game variant

You are playing a game with your friend on a $7$x$7$ grid board. In every turn, you begin by putting a $0$ (zero) on any empty square on the board, and then your friend puts a $1$ (one) on a different ...
3
votes
1answer
271 views

100 Prisoners and 3-state clock

100 Prisoners and a clock seems far too easy on the prisoners, so the exact same question, except that they must change the clock by exactly 4 hours: There are 100 prisoners who are given a chance at ...
2
votes
1answer
161 views

Adding up divisors of integers

Alice and Bob play a game, taking turns. Alice starts and writes an integer between 1 to 10 on a blackboard. Then Bob adds any integer between 1 to 10 to this number and writes it on the blackboard. ...
1
vote
1answer
270 views

1 lion, with a zebra and a fixed enclosure

Background See the puzzle Variant of lion and 100 zebras from @ghosts-in-the-code which remains unsolved years after it was posted. Several times in the last couple of years I've started to write up ...
22
votes
5answers
2k views

retsubkcolB Spelled Backwards

How would you enter retsubkcolB spelled backwards into the comment box below and press the "Add comment" button (nothing will happen, as there's only 11 letters) using at most 10 clicks in ...
-4
votes
6answers
723 views

Variation of 100 coins puzzle (no flipping) [closed]

You have 100 coins laying flat on a table, each with a head side and a tail side. 10 of them are heads up, 90 are tails up. You can't feel, see or in any other way find out which side is up. You ...
5
votes
1answer
256 views

How did the king pay the worker? [duplicate]

A humorous king pays his worker with one inch gold bar everyday. He had a $31$ inches gold bar and he paid the worker $31$ days of a month cutting it in just $4$ places. How is this possible? Taken ...
23
votes
7answers
2k views

What is the minimum number of helpers that an explorer need to cross the desert?

There is a desert which can be crossed only by walking and this takes six days. The explorers of the desert can carry at most four days' water and food. If they want, they can take helpers with them. ...
7
votes
4answers
948 views

How did the criminals escape from the jail?

There are $72$ criminals in a jail in $8$ cells as shown in the picture above. There are $9$ criminals in each cell. There are $4$ guards. Each of them watch over the $4$ corridors. As there is a door ...
-2
votes
1answer
247 views

The Box of Tic-Tacs

You were kidnapped and had no way of escape. The kidnapper opens the lights, and in front of you is an opened box of Tic-Tacs. He claims that he ate from 0-5 Tic-Tacs, (with 60 from the newly-bought ...
1
vote
1answer
195 views

Catch the fugitive

The fugitive is at the origin. He moves at a speed of 100. You have a guard at every integer coordinate except the origin. A guard's speed is 1. The fugitive and your guards move simultaneously and ...
21
votes
3answers
3k views

Can you survive this infinite zombie attack?

You're surrounded by infinitely many zombies. You're at the origin, and zombies occupy the points $(100i,100j)$ for all integer $i, j$ except the origin, as shown below: You and the zombies move ...
2
votes
1answer
77 views

Peg Solitaire variant: from 48 on an 8x8 board

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 ...
7
votes
3answers
462 views

Can you find and capture a shapeshifter?

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 ...
4
votes
0answers
224 views

One vs many. Can white force a draw?

On an infinite chessboard there's a single white king and N black kings. The nearest black king must be K moves away from the white king. Given N, white dictates the value of (finite) K, then black ...
7
votes
2answers
318 views

Can the fugitive escape?

A fugitive is surrounded by N police officers, with the nearest one at distance 1 away. The fugitive and the officers move alternatively. In a fugitive move, the fugitive can travel no more than a ...
5
votes
1answer
486 views

Best strategy for stick-taking game

Rules of the game: It's a two player game. Moves will alternate between players. There are N sticks on a table. A value M is defined at the start of the game such that 2 < M <= N. On their turn,...
7
votes
2answers
461 views

Judgment-free construction of a playlist

Alice and Bob are planning a long car trip and need to come up with a playlist for it. For any given song, they have one of four opinions on it: "That's, like, my favorite song ever" (love), ...
12
votes
3answers
775 views

Outmaneuver your opponents in the duel

A, B and C are in a three way duel. Starting with A, they rotate in the order of A-B-C, each firing one shot at a time. They stand close to one another, so that each can kill one of the others or ...
5
votes
1answer
305 views

Two players alternately name dates

Two players alternately name dates. The winner is the player who names 31st December, and the starting date is 1st January. If a player names Xst of Y Month, the other player can name the first of the ...
16
votes
7answers
2k views

Flashlight and 8 batteries

A flashlight requires 2 AA-type batteries to operate. Both these batteries need to be charged for the flashlight to provide light. We happen to have 8 batteries, but 4 of them are charged while the ...
7
votes
4answers
785 views

Sorting 6 boxes by selecting 3 boxes each time

There are 6 boxes, each containing a distinct number. You can select 3 boxes and the Oracle will tell you which box has the smallest number and which has the largest number of the three selected boxes....

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