Questions tagged [strategy]

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

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votes
3answers
853 views

Five pirates splitting gold with a twist

Source: This was posted on the Grey Labyrinth Forums many years ago. The five pirates are back. But this time one of them has the dreaded Zanzibar fever, whose terrible effects are spelled out below....
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3answers
810 views

Greedy Chocolate Eaters

Alicia and Bobby play a game with a rectangular chocolate bar, scored into an $m$ by $n$ grid of squares. The children alternate turns, with Alicia going first. On a child's turn, they must break ...
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3answers
231 views

The game of Shafiqa and Habibi

Shafiqa chose a positive integer number $X\le100$, and Habibi is trying to guess the number. Habibi can select two natural numbers $M$ and $N$ less than $100$ and ask about the greatest common ...
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4answers
700 views

Nerves of Steel (a dice game)

A carnival offers a game, called Nerves of Steel. It is played with a standard die, except that the "six" has been replaced with a skull. You start by paying $7, then rolling the die. Each time you ...
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2answers
990 views

Minimum number of steps in which these people can rearrange themselves?

5 persons numbered 1 to 5 are standing in a row at 5 spots. 1 2 3 4 5 Any person can call another person among the remaining 4. When someone calls someone else, the person who was called ...
10
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1answer
190 views

A short but stimulating robot-control puzzle

The goal of this puzzle is to find a sequence of max 4 commands that will move the triangle through the maze and visit all colored squares. Three types of commands can be used: F0 makes the sequence ...
10
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1answer
313 views

A programming puzzle without code

The goal of this puzzle is to find a sequence of max 5 commands that will move the triangle through the maze and visit all colored squares. Three types of commands can be used: F0 makes the sequence ...
10
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3answers
1k views

The Expedition Into The Ancient Cave

You are a archeologist and have taken 8 of your students on a expedition trip to a ancient cave to try and find ancient treasure. After you and your team entered the cave, you travel as a group ...
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3answers
2k views

Precision Tag - can the lion win?

This is a spin-off motivated by Lopsy's interesting variant of Gamow's lion and zebras puzzle. It arose from a line of enquiry that tried to extend the vertical run past 5000km (or characterise the ...
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3answers
242 views

Find a good strategy to survive the multiplayer duel

Alice is involved in a duel with $N$ other opponents. She can choose a gun for herself with any hit probability as she wishes. She also prepares guns for her opponents, whose hit probabilities she can ...
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4answers
1k views

Rocks and Lever (Game) - Goofspiel

I am not sure if there is a name associated with this game but I do not know of one. There was this 2 player game I had once played, and I am wondering if there is a winning strategy. The game is as ...
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3answers
363 views

Wizard's Labyrinth

A thief has snuck his way into the wizard's castle. After traversing a plethora of magical traps and illusory walls, he finally spies the wizard's hidden stash of gems beyond the end of a long ...
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1answer
394 views

Is Oh Tetris Oh! always a draw?

Alice and Bob were playing Oh-Tetris-Oh!, when they decided that every game must be a draw (played intelligently). Can you prove this? (Oh yes, the rules: A $10\times10$ grid, you can pick any ...
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1answer
320 views

Reverse dots and boxes – Guess the last move

Alice and Bob are playing a game of reverse dots and boxes. The players take turns adding one horizontal or vertical line of size 1 in one free spot on the grid (marked with light gray lines ...
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0answers
293 views

Quantum tic tac toe strategy

Most of us learn tic tac toe early in our life. Also, it is easy to find an optimal strategy for playing. How about Quantum tic tac toe? What is the optimal strategy for playing it? Rules On a ...
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5answers
9k views

River Crossing Puzzle

There is a family which contains 4 members: Dad, Mom, Son, Daughter. They have a boat which carries only 100 kg at a time. Mom and Dad weigh 100 kg each, while Son and Daughter weigh 50 kg each. ...
9
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3answers
3k views

Queen chasing a knight (chess pieces)

There is a player who controls only a queen, while his opponent controls a knight. Both pieces start from opposite corners of the board. The aim is to kill the knight, without having your queen killed....
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4answers
1k views

The Universe and Spaceships

It is given that there are infinite planets in the universe and every planet has exactly one spaceship on it. (Thus there are infinite spaceships too.) The distance between planets is unknown. As ...
9
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2answers
433 views

How to beat Count Dracula, part 3

This is a follow-up to "How to beat Count Dracula" and to "How to beat Count Dracula, part 2". Abraham Van Helsing and Jonathan Harker play a game against Count Dracula. The three players agree on ...
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5answers
658 views

Salary sum with a twist

You've been considering your boss' offer, when you decide to try and sort things out for yourself. So, armed with your thought reading device, you set out to find the total salary of all the employees....
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4answers
574 views

4 function calculator puzzle

You have a basic but very problematic four function calculator. That is, the keys are 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, +, -, x, /, and =. However, all the keys are scrambled up in an unknown order, and ...
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3answers
1k views

n - archers and many arrows

Suppose there are n archers in a standoff and want to kill each other until there is just one archer remaining. However everyone's chance of hitting (and thus killing) another archer is not fair. ...
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2answers
662 views

Middle weight puzzle

There are 100 white and 101 black balls. All the balls have different weights. Balls of the same colour look the same. White balls are numbered from lighter to heavier (from 1 to 100). The same is ...
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4answers
451 views

Number exchange game

Inigo and Vizzini are to have a battle of wits to the death. The rules are: Inigo is given two independent random numbers uniformly distributed between 0 and 1. Inigo chooses one of the numbers to ...
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2answers
246 views

You Sign Me Right Round

This is a 9x9 grid, with a sign in the center cell like shown. You can add signs to this grid one at a time following these rules: Each sign placed must point to the next sign placed Placed signs ...
9
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5answers
302 views

Find the optimal strategy for this dice game

You are playing a game: You have $6$ standard 6-sided dice that are all rolled at the start of the game. The sum of dice values is your score. Each turn, you can take any (or none) dice and reroll ...
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2answers
4k views

Color the Table

Color each cell of the table with following rules: Yellow and Orange cells are adjacent, but Red and Black are not. Cell with number 3 is White, Green, Blue or Red and the cell with number 5 is not ...
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1answer
715 views

Pirate Puzzle Double Twist

Five pirates, fresh from their first bout of pillaging, return to their island base to celebrate and divide up the treasure. While this was their first time working together, the start of what they ...
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3answers
2k views

A puzzle of trust and lies, allies and spies

Here is a puzzle involving distrust and asymmetric knowledge. (It was inspired by, but not exactly following, the board game The Resistance: Avalon.) There are ten resistance fighters trying to ...
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3answers
2k views

Sliding Bolt Puzzle - fastest solution (time-wise)

This is a follow-up question for the Sliding Bolt Puzzle. If you have not solved it yet, you might want to head there first, as the extended discussion of its solution in this question will contain ...
9
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1answer
546 views

Optimal building strategy puzzle with airdropped mining bases

The general from Optimal Building Strategy Puzzle is in a conflict with another general. This general is from another faction with 3 major differences in his technology: Instead of the worker having ...
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3answers
3k views

Speak without using the letter “b” [closed]

A voice recognition software crashes from using the letter "b", but you need to test it. You have to speak continuously for about an hour, using meaningful words, but you cannot repeat words, and you ...
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2answers
2k views

Entangled physicists

The anti-intellectuals have won the war, and under the iron rule of emperor Nonotin anyone who has been deemed too smart for their own good has been brought to labour camps. But most of the science ...
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6answers
1k views

Optimal next move in minesweeper game?

In order to solve this minesweeper game, what is the optimal next move? A description of the game can be found here: https://en.wikipedia.org/wiki/Minesweeper_(video_game) I do not have the answer ...
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2answers
7k views

Strategy for solving Flow Free puzzles

There is an app on the app store called Flow Free. Basically, there is a grid with a few sets of colored dots, and you need to connect each dot to the other dot of the same color, filling up the ...
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4answers
4k views

Battleship Game with only one Aircraft Carrier

Two guys are playing regular battleship game with only one Aircraft Carrier, with dimensions $5\times1$. Their table is regular $10\times10$ Battleship game grid board. One guy places his Aircraft ...
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2answers
733 views

Lots of Gold Golden Coins and a Scale

Following my previous question: Lots of Gold Stacks and a Balance Scale You are given 10 stacks, each stack consisting of N golden 10g-coins and a digital scale with perfect precision that shows ...
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3answers
1k views

Card game rigging

You and your friend are playing a game with a deck of cards numbered 1 to N. You will first put the deck of cards in whatever order you want. Next your friend will choose an option: "A" or "B". ...
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1answer
2k views

99 chips into more chips

You are at a casino in Vegas and you have earned 99 chips by playing poker! While you are checking out a slot machine, someone comes to you and congratulates you that you have a chance to make more ...
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5answers
1k views

The Great Houdini's awesome card guessing trick (2)

The Great Houdini is performing again! Everybody wants to see the famous magician and the magic show is sold out. Today Houdini shows the following sophisticated trick: A guy from the audience ...
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7answers
1k views

7 Numbered Balls Game

You are walking on the street and notice a guy gambling with some other guys and you start to watch. The game principle is pretty easy. There are 7 balls in a pouch and you have 3 balls to draw ...
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3answers
2k views

Reverse the order of 8 poisonous substances

8 very poisonous substances named s1 to s8 are kept in a safety room. The substances are kept in ascending order (s1,s2,s3,s4,s5,s6,s7 and s8). In the room there are 3 robots. First robot can "rotate ...
8
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1answer
556 views

Picking A Number Game

Alice and Bob play a game starting from Alice where Alice and Bob are supposed to write a number to the board, Then the game goes through several rounds between Alice and Bob with the rules below: ...
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3answers
1k views

30 fake coins out of 99 coins v2

Follow up question to my other question, but totally different methodology required. You are given 99 coins which consists of 30 fake ones. You also have a digital balance scale with perfect ...
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4answers
539 views

Maxit negotiations

Your military junta has recently overthrown the government of Malta and taken control of the small island nation. As a way to finance your wise and just dictatorship, you have decided to threaten the ...
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2answers
525 views

Guess n binary digits

There's a N (1 ≤ N ≤ 1 000; N is pair) digit binary number and you have a maximum of 2050 guesses to find out which is it. With each try, you will know one of the following: You got it right (100%); ...
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3answers
381 views

Four-in-a-line Puzzle

Disclaimer: This is an open-problem, I don't have a complete solution for this puzzle yet. We are playing a $2$-player game: you as a challenger and me as a judge. Initially, there is an empty ...
8
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1answer
708 views

I am caught when I was about to steal some candies

I am a eight years old boy, I love candies, but my mom does not want me to eat any more candies because I start to have black teeth :( but I still love candies so... Today when I was about to steal ...
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6answers
1k views

Devious auction game

Saw this on TV today: A man is auctioning a real $20\$$ bill. There are a vast number of bidders. A person may make as many bids as he wants. The starting bid is $5\$$. No $2$ bids must be ...
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2answers
1k views

Getting Stuck on Purpose

Consider the following building floor plan, with a set of rooms labeled A-G and an Outside:                   ...

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