Questions tagged [strategy]
A puzzle whose solution is a methodological plan of action for realizing a specific goal.
507
questions
5
votes
1answer
462 views
Playing blindfolded 2048
Suppose you are playing many 2048 games, all blindfolded. As usual you can press left, right, down, or up to move the tiles. When there are no more moves the game terminates and you are told your ...
0
votes
3answers
116 views
playing “Coins on a table” against a distracted friend [duplicate]
This puzzle is a follow-up of Coins on a table (warning: the link contains the answer to the original question).
You are playing a game against your friend Alice:
first Alice places one coin on a ...
18
votes
2answers
2k views
Playing with one Queen on a chessboard
Alice and Bob play a special chess game with alternate moves. Alics starts with an empty chessboard and puts a Queen at a field in the first row (A8-H8) or the right column (H1-H8). Now Bob is moving ...
0
votes
1answer
184 views
Holmes, Scrambled
Tired of the constant challenges Holmes was setting me, I decided to set him one of my own.
“Here’s a conundrum for you, Holmes. How long a word you can make from your own full name? That is, to say, ...
2
votes
1answer
114 views
Four unfair dice
On a table there are four standard six-sided dice with faces numbered 1, 2, 3, 4, 5, 6 each.
Alice starts and chooses a die. Then Bob chooses a die and both throw the dice.
The winner is the person ...
13
votes
8answers
3k views
How could Larry get his friends on a plane without knowing their weights? [duplicate]
This riddle was inspired when I watched the latest (as of this post) episode of Curb Your Enthusiasm (S10E4), in which Larry is faced with a dilemma that he never really solved. The dilemma is as ...
12
votes
3answers
967 views
The Troll, the dwarves and the gloves
A group of $N$ dwarves are caught by an evil Troll. As usual the Troll gives the dwarves a chance to escape if they solve a puzzle he created just for the occasion.
Tomorrow morning each dwarf will ...
20
votes
1answer
821 views
Unbalanced weight of boxes
You are given a traditional balance scale with two pans (no reading) and 6 boxes with the following properties:
1) the weight of each box is a positive integer number
2) if you put any number of boxes ...
10
votes
1answer
363 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 ...
10
votes
3answers
339 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 ...
2
votes
3answers
1k views
The missing number
The integer numbers from 1-30 are mutually communicated to you one by one in a random order (one number about every 5 seconds).
However exactly one of those numbers is not communicated.
What is a ...
10
votes
0answers
264 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 ...
3
votes
2answers
118 views
How to effectively hide an earth rebooter thingy [The Good Place Season 4 spoilers]
This puzzle is unsolved. I don't know if there is a solution or how to solve it. I'm also not sure what type of puzzle this would be, so if anyone wants to correct the tags, feel free.
Imagine you ...
0
votes
0answers
210 views
A Logician's Game of UNO Flip
Two players are in the middle of an ongoing one-on-one game of UNO Flip, with all its standard rules in effect.
Play is currently Light Side Up. It is Player B's turn. Player A has 3 cards remaining, ...
11
votes
5answers
432 views
Crossing the desert
There are explorers that want to go as far in the desert as possible. One explorer can carry water for himself for 10 days. If they would all stick together, they would have enough water to go 5 days ...
10
votes
9answers
2k views
Find two coins using a balance scale
You are given 20 identical coins. 18 of those coins have a weight of 10g each, 1 coin has 9g and 1 coin has 11g.
You are given a traditional balance scale with two pans (no reading).
What is the ...
14
votes
1answer
365 views
A flower-shaped robot-control puzzle
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 ...
30
votes
1answer
3k views
How to get a bowl with one liter of water
You are given a rectangular bowl with size 5 x 30 x 40 cm and you should put exactly one liter of water into the bowl. You go to your kitchen, where you can put the water directly into the bowl from ...
-1
votes
1answer
131 views
Find the lowest floor from which Venus eggs break [duplicate]
Venus gave you two eggs because she wants to test their strength.
She lives in a 100 floor building and she wants to find the first floor above which the eggs break when thrown out of the window.
...
8
votes
1answer
248 views
Maximizing Product of Selected Cards
Jennifer is playing a game. The Ace through King of spades are taken from a standard playing deck and laid out facedown on the table. At any time, Jennifer can select two cards and reveal them, and ...
7
votes
1answer
224 views
A Bored Jailer and His Number Game
A bored jailer tells a prisoner that if he can guess a secret number he will be set free. The rules are given that the number will not be more than three digits in length and the prisoner may guess ...
15
votes
2answers
603 views
United States Towns/States Traversing by Name Puzzle
I’m new to puzzle solving in a structured way, so please go easy on me, but I thought the following was interesting (sorry if it’s not or seems like grunt work). I came up with this while staring ...
-6
votes
1answer
120 views
Another how to kill 7 submarines
7 submarines are placed on an x, y grid - 0 to 111. They are located on whole numbered locations. Each submarine starts from any selected location with a given fixed speed and fixed direction, ...
6
votes
1answer
298 views
Russian Roulette (Redux!)
You are challenged to a game of Russian roulette with a six-chamber revolver, but you and your opponent are allowed to change the outcome of the game in different ways. Here's how the game will ...
1
vote
1answer
168 views
How to kill 7 submarines
7 submarines are placed on an x, y grid - from negative infinity to positive infinity. They are located on whole numbered locations. Each submarine starts from a location with a given fixed speed and ...
8
votes
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 ...
12
votes
3answers
2k views
Can you catch the thief?
This was a puzzle I recalled from university a couple of years back. I don't know what the original puzzle is but if someone knows it, please let me know so I can credit the source.
You are a police ...
12
votes
3answers
2k views
Find number 8 with the least number of tries
You and your friend plays a game. In this game, there are numbers written on the cards from 1 to 12 on one side (so 12 cards in total). The other side is blank. You can write anything on the blank ...
6
votes
3answers
363 views
Line segments inside a square
A set of line segments inside or at the edge of a square with side length 1 should be positioned in such a way,
that any straight line going through the square must touch or intersect at least one of ...
11
votes
2answers
2k views
Three knights searching for a princess in a castle
There is a castle with rooms arranged in a 4x4 square grid. The princess living in the castle sleeps in a different room each night, but always one adjacent to the one in which she slept on the ...
4
votes
1answer
327 views
Two knights searching for a princess in a castle
There is a castle with rooms arranged in a 3x3 square grid. The princess living in the castle sleeps in a different room each night, but always one adjacent to the one in which she slept on the ...
10
votes
1answer
184 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 ...
7
votes
2answers
299 views
Marbles on a Mancala Board
I would like to introduce an ancient African board game I've just invented.
Until someone comes up with a better name, it's called Marble Mancala.
The rules are pretty simple:
There are two ...
1
vote
1answer
165 views
Don't Fail MY Exam [duplicate]
A professor decides the following grading scheme in his class. After the final exam is graded, he keeps all the papers upside down on his table in a random order so that no student can recognise his ...
5
votes
2answers
272 views
The Wires Underground [duplicate]
There are ten wires that run underground across a river. Thus on each of the banks, there are ten ends of the wires. Unfortunately, given an end of a wire on this bank, one doesn't know which end on ...
4
votes
2answers
127 views
12 balls 1 scale with 4 groups
So, we all know the famous 12 balls 1 scale riddle. It has been here repeated many times, however, the provided solutions always start with splitting the twelve balls into three groups of four. This ...
2
votes
1answer
157 views
Sleeping Beauty Study at the Institute of Mad Science [closed]
You've been approached to assist in the furtherance of SCIENCE as a research subject at the Institute of Mad Science (local branch)!
The experiment you'll be involved with is called the Sleeping ...
6
votes
2answers
147 views
Positioning cards labeled with numbers from 0-9
Ann and Bob play a game. On a table there are 10 cards which are labeled with number from 0 to 9 each. Bob is allowed to change the position of the cards with a sequence of his preference. When he is ...
5
votes
2answers
126 views
A pile of chips involving powers of 2
Ann and Bob play alternately on a pile of chips. On each play, any number of chips, which is a power of 2 (including 1=$2^0$), can be removed from the pile.
Obviously the number of chips to be removed ...
6
votes
1answer
175 views
A pile of chips involving primes
Ann and Bob play alternately on a pile of chips. On each play, either 1, 2 or 3 chips can be removed except if the number of chips is a prime number. In that case either 1, 2, 3, 4 or 5 chips can be ...
10
votes
1answer
292 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 ...
2
votes
6answers
218 views
Two untrusted traders [closed]
I'm sure this has been asked before, but I tried searching and couldn't find it. I don't know the solution, and it is possible there isn't one.
There is unsavoury pirate and an unscrupulous merchant....
1
vote
1answer
118 views
How Should I Go About Answering Square Spin Puzzles?
The Square Spin series of puzzles is a bit abstract. There is quite a lot for newcomers to digest and getting started may be daunting. Even if you thoroughly read the rules and intend to attempt one ...
12
votes
1answer
667 views
Reverse dots and… cubes? - Snowflake edition
A Reverse dots-and-boxes puzzle inspired by @jafe
Albert and Robinson are playing a game of reverse dots and boxes.
The players take turns adding one plane in one free spot on the grid (...
8
votes
2answers
722 views
Reverse dots and boxes, swastika edition
Alistair and Roberta are playing a game of reverse dots and boxes.
The players take turns adding one horizontal or vertical line in one free spot on the grid (marked with light gray lines in ...
14
votes
2answers
711 views
Reverse dots and boxes
Alice and Bob are playing a game of reverse dots and boxes. The rules are simple:
The players take turns adding one horizontal or vertical line in one free spot on the grid (marked with light ...
19
votes
3answers
1k views
Where are the Wazirs?
A wazir is a fairy chess piece that moves like a rook, but can go only one square.
&...
6
votes
1answer
220 views
I'm a Proper Divisor
Ann and Bob are playing a number game. Ann starts with the number 60. Then she subtracts a proper divisor of 60 from it. Bob then takes the number Ann made and subtracts one of its proper divisors ...
8
votes
1answer
288 views
3D Chess - Stale NBA (kNight-Bishop Assault)
This is my very first chess puzzle. Any constructive feedback is more than welcome. Thanks!
Introducing 3D Chess!
To make things simple for the first time, we are using a $3\times3\times3$ ...
12
votes
4answers
531 views
Red and White Squares
There are two grid boards with the dimension of 9x9 and 14x14, consist of all white squares. You are supposed to color some squares with a red color on the conditions below:
In a board, if two square ...
