Questions tagged [mathematics]

A puzzle related to mathematical facts and objects, whose solution needs mathematical arguments. General mathematics questions are off-topic but can be asked on Mathematics Stack Exchange.

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3
votes
3answers
86 views

How to measure 5 litres using 10l, 7l and 3l vessels

A milkman have 10 litres of milk in a 10 litre vessel. He has two additional vessels of 3 litres and 7 litres. One customer need 5 litre milk. He measured 5 litres using those 3 vessels. How?
9
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2answers
492 views

Cut this shape into 3 pieces and fit them together to form a square

A shape is drawn on a sheet of squared paper as shown in the picture below. The shape is then cut from the sheet and given to you. You are asked to first make a straight cut across the shape and then ...
2
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1answer
136 views

The Big Cube and Squares Puzzle

The following logical puzzle is mainly inspired by a mathematical contest I went to. Part A You are given a cube. How many planes cross this cube by at least 3 vertices? This number will be named $...
5
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1answer
134 views

Project Projection

The Project You and a co-worker have been assigned to complete a web application. The client wants to know how many hours the project will take to complete - the minimum. Your Puzzle Task You need ...
3
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1answer
277 views

Relation between the following numbers

If: $4+2=6$ $2+8=26$ $5+8=109$ $7+4=225$ Find $8+6=?$
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0answers
724 views

Solve this problem [closed]

⭕TMF తెలంగాణ గణిత ఫోరం ఈ లెక్క చెయ్యండి చూద్దాం నలుగురు ఫ్రెండ్స్ ఉంటారు.👬🏻👬🏻 ఆ నలుగురు స్నేహితులు నరేంద్రుడి తోట వద్దకు🌴🌴🌴 వెళ్లి అక్కడ కొన్ని అరటి 🍌పండ్లు తెచ్చుకుంటారు. తోట ఇంటికి చాలా దూ...
1
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0answers
76 views

Ranking boxers in order of their strength in minimum number of days [closed]

1024 boxers are to be ranked in order of strength: The following are given: No two boxers have the same strength In any match, the stronger boxer always wins A boxer may fight in only 1 match per day ...
0
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0answers
119 views

How to solve this maths puzzle? [closed]

How can I solve this maths puzzle?
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0answers
125 views

Please ! Answer this puzzle [closed]

How should the numbers be filled in in this arithmetic grid?
3
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1answer
292 views

Complete the series:

$4427, 827, 67, 31, 9, ?$ Choose between: (a): $7$ (b): $6$ (c): $5$ (d): $4$ Looking at the numbers I think that there must be some exponential relationship but couldn't find it. I took the ...
7
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2answers
496 views

Knights and Queen puzzle

This is not original. I just want to share this problem. If you have heard of it, please give opportunities for those who haven't to answer. Horst and Queenie are playing a game on a $200\times200$ ...
8
votes
3answers
311 views

Rock, Paper, Scissors, Anti-Rock

Alice and Bob are both well-known perfect logicians who have the ability to internally randomize and often pass their time by playing rock-paper-scissors. One day, tired of the usual RPS game, Alice ...
3
votes
3answers
424 views

Something I loved the most

Below are some puzzles you need to solve to make a 4 letter word. 1. 105 35 315 ? 2. I am the most important element in your surrounding. I was found by a Scottish physician. Who am I? 3. I am ...
3
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3answers
1k views

Brain twisting maths sequence question

The answer is But what is the explanation?
9
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3answers
402 views

Number Guessing (Part 1)

I thought up two positive integers with product less than $500$. I told their product to Penny, and their sum to Sandy, and told both of them the constraints and they are both perfect logicians. ...
4
votes
1answer
171 views

My friend's next country

My friend gave me this puzzle. Here is the list of the places I went to, in this particular order, and their scores. United States (USA) 1890.19 Soviet Union (URS) 860.14 France (FRA) 749.02 ...
1
vote
1answer
59 views

k-threats Chinese Cannons Chess: Part 2

Inspired from the N-Queens problem, I here propose you a puzzle from Xiangqi wich is Chinese Chess equivalent, mostly played in Asia. The most different piece from Xiangqi is the cannon. You can ...
4
votes
1answer
67 views

k-threats Chinese Cannons Chess: Part 1

Inspired from the N-Queens problem, I here propose you a puzzle from Xiangqi wich is Chinese Chess equivalent, mostly played in Asia. The most different piece from Xiangqi is the cannon. You can ...
3
votes
1answer
149 views

Math Puzzle: Totaling up A,B, C [closed]

We know the following about the numbers $a$, $b$ and $c$: $$(a+b)^2=9,\quad(b+c)^2=25, \quad(a+c)^2=81$$ If $a + b + c ≥ 1$, determine the number of possible values for $a + b + c$
5
votes
1answer
368 views

An extremely fair die

I have in mind a special kind of die, one that is even more fair than uniform density dice. If the die has $n$ faces with labels going from $1$ through $n$, then some faces will be larger than others ...
10
votes
3answers
502 views

Pieces of paper without consecutivity condition

TL;DR: like this puzzle but with an arbitrary number of papers and without the condition that the papers chosen must be consecutive. You are given $n$ pieces of paper, and you write down $n$ distinct ...
5
votes
2answers
454 views

4x4 Grid with multiple solutions

Consider the following 4x4 grid : 972 9 5 55 18 22 x 28 50 24 25 26 7 400 52 4 Find $x$. However, as the title suggests, there are multiple solutions. You have to ...
14
votes
3answers
1k views

A mini game with 15 pieces of paper

You are given $15$ pieces of paper, you are asked to write down any distinct integer numbers on them as you wish. Then these pieces of paper will be turned back, mixed and put on the table in a ...
3
votes
0answers
204 views

3 x 3 Grid Square Problem

For a question that I need to answer, we have to show that there is only one arrangement for which, in a 3 x 3 grid in which the numbers from 1 to 9 are placed and 5 is the centre number, the sum of ...
13
votes
3answers
803 views

Football Rivals

Team A and Team B are perennial football rivals. Every year they meet for a series of games. The first team to win four games gets to take home the Golden Teapot and keep it for a year. The teams are ...
3
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2answers
239 views

A pair of number squares

Given these squares of numbers (maybe you can even solve it with just one!): 9 6 2 8 x 7 7 7 1 What is the value of x? While the accepted answer ...
3
votes
1answer
171 views

What is the missing number in this grid composed by 25 values?

Well, I have created a simple table with 25 values, inside it, all the data is readable, except for one that is hidden. Can you guess it? The table:
5
votes
1answer
1k views

How to programmatically solve math puzzle

I have this puzzle and I want to solve by code. I wrote simple code trying to brute force but it fail in one condition https://dotnetfiddle.net/cJyu3w Anyone know of a link or source how to solve ...
0
votes
2answers
416 views

A 'Game of Thrones' maths puzzle

Four prisoners escape from the dungeons at King's Landing and head for the Wall; a distance of 700 leagues. The Maester travels 1 league in the first day, then each subsequent day, doubles the ...
5
votes
2answers
109 views

Determine a polynomial with nonnegative integer coefficients with minimum queries

A friend of us makes up a polynomial with nonnegative integer coefficients. Our task is to find it out with a minimum number of queries. For each query we give him a nonnegative integer $L$ and he ...
6
votes
1answer
124 views

Most moves by Most number of Pieces

Using one color, White or Black, place as many chess pieces (kings, queens, bishops, knights, rooks, and pawns, or combinations thereof) as you can on a checkerboard so that when the number of pieces ...
-5
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2answers
131 views

You can solve this!

Can you solve this? 1=2 3=18 5=50 4=32 Then 6=?
6
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2answers
136 views

Squared, what is in the post-scriptum?

Just received an invitation from a fellow mathematician for a party. The invitation is quite clear: where I need to be at what time is clearly said in the invitation, but at the bottom of the ...
13
votes
2answers
414 views

It cannot be done. I think

I have spent too much time on this question. I am convinced this cannot be done. Please prove me right (or wrong) and explain why. Below is a 5x5 grid. Digits 1 through 9 go in the 9 yellow boxes. ...
1
vote
0answers
167 views

Math tapestry puzzle #3

Continuation from Math tapestry puzzle #2 Now things are heating up, it looks like this is slowly becoming bigger. I saw my friend Anna working on her tapestry. She asks me, "Do you like it?" ...
5
votes
2answers
198 views

A different kind of math problem

A different kind of math problem $\text{If }$$(2+5=8),\ (8-3=1),\ \text{and}\ (4+3 = 9),$ $\text{Then, what is } (8-6+5) ?$ Bonus: $\text{If }(8 - 2 + 7 + \text{P} = \text{A})$, $\text{Then what is ...
-2
votes
2answers
296 views

Make the numbers 1-50 using the digits 2, 0, 2, 0

Try to make all the numbers from 1-50 using 2, 0, 2, 0 exactly once. Rules: Use only the operations +, -, *, /, !, exponents and square root No rounding eg. ...
0
votes
1answer
96 views

Math tapestry puzzle #2

This continues from Math tapestry puzzle #1. Find the rules there. Continuing on from that, I saw my friend Jason come outside. We had a conversation about the things that are here. Suddenly he says: ...
11
votes
1answer
433 views

Can you decipher these ancient numerals?

This stone was found at the foot of an ancient door. This old note with some mathematical relationships was discovered nearby. Can you use this information to figure out what number each of the 9 ...
8
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1answer
124 views

Cipher puzzle - Cryptography of the day

I received this in my email: Kpa nfwa jnjnbb vo Sk kizk auy phurtpijd? Solve it.
2
votes
1answer
66 views

Sequence Puzzle - Sequence Of The Day

Look at these two sequences. The rules of these two sequences are the same. 0 32 15 3 9 5 4 2 6 7 13 110 174 155 314 2120 5360 24671 119546 193002 240820 274454 153700 1397287 17916598 26245242 ...
2
votes
1answer
160 views

Math tapestry puzzle #1

I went outside. I saw several math tapestries. Apparently they mean something. What goes in spot NN? I know from my friend that... Two adjacent numbers always have the same sum. The 4 numbers in each ...
3
votes
0answers
170 views

Encrypted growing sequence

The following sequence has been encrypted: 1-0 3-0 6-1 ...
14
votes
2answers
621 views

Shots, shots, shots, shots!

Once in a while I go out for a drink to my favourite bar. Normally is just drink a beer, eat some snacks and have a good time with my three friends. But last night I wanted to do some shots. The ...
12
votes
2answers
1k views

Who would be the first to defeat an abundant number?

Rupert and Jenny are playing a game. Each player's score starts out as the number $94083986096100$, which is the square of the product of the first 8 primes and therefore has a lot of divisors. We'll ...
7
votes
1answer
382 views

What are the missing 7 numbers?

Below a sequence of numbers is stated, I'm looking for the 7 missing natural numbers which should replace the 7 x's. Counting will give you information which can be neither positive nor negative. ...
1
vote
3answers
190 views

How to visualize the tasks for the rope and nails puzzle?

Following the A&Q I want to visualize the tasks for the rope and nails puzzle. In the paper, one can see 11 puzzles: Puzzle 1 (1-out-of-3) Hang a picture on three nails so that ...
3
votes
1answer
93 views

Tragedy of Linearity

My prefix is too much. My infix begs for vertical bars. My next infix has the least concern. At the end, all I have is a 'd'. Together, I imply no solution. What am I?
7
votes
1answer
147 views

Guessing the coin flips [duplicate]

Two prisoners, Alice and Bob, are captured by a dragon and placed in separate, isolated cells. The dragon then flips an infinite number of fair coins, and tells the outcomes of odd throws to Alice and ...
12
votes
2answers
2k views

It's my sister's birthday

I'd ordered her a cake, but when I got to the bakery to pick it up, the cake decorator had transposed the digits of her age. "She'll thank you for the compliment," I said, "but her age is a prime ...

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