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Questions tagged [calculation-puzzle]

A puzzle that involves numerical calculations, such as multiplication and addition.

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9
votes
1answer
458 views

Arrange numbers into the quadrilaterals

Arrange numbers 1 to 14 to the quadrilaterals, such that: The difference between 2 numbers in squares having a common edge or corner is greater than 2. Numbers inside the green quadrilaterals are ...
4
votes
3answers
1k views

Gumball Machine Logic Math Puzzle

You walk into an antique shop and find an unusual gumball machine. On the back of the gumball machine you can set and lock five dials with the following labels: Percentage (0% through 100%) Pink (0 ...
2
votes
1answer
217 views

Generate a valid string

I have been observing her for just over a week now. She had seen me but didn't know she was being watched. As people pass she hands them a piece of paper. Some even stop and put money in a cigar box ...
0
votes
1answer
250 views

Help with this puzzle?

Here is a set of problems that I encountered during an examination. Can anybody help me find the numbers where the '??' symbols are? $\begin{bmatrix}10&6&2\\15&31&?? \\15&96&7 ...
14
votes
4answers
3k views

Mother and Daughter

A mother (not yet a centenarian) and her daughter (who happens to share her mother's birthday) are both a prime number of years old. Moreover, in their lifetimes there have been at least a dozen other ...
15
votes
2answers
2k views

What am I worth as a TART?

I hope it's not too easy. As CAKE I'm worth 573,566. As PIE I'm worth 33,062. What am I worth as a TART? Note : It's not a word game.
5
votes
5answers
505 views

Move a number's position to get the right equation

$62-5+3*2=25$ Move a number's position in order to get the right equation.
2
votes
2answers
304 views

Macbook air falls off x floors and survives! [duplicate]

You've just bought an anti-shock skin for your macbook air and want to make a review video for your vlog showing how good it is at absorbing shocks. The skin has a special property that either ...
7
votes
2answers
2k views

Prime sums in a 4 x 4 board

Place the integers 1 to 16 in the sixteen cells of a 4 x 4 board so that the sum of any four numbers in a row or column is a different prime.
5
votes
1answer
529 views

Rolling a dice - Expectation Question [closed]

I heard / read / acquired this puzzle from somewhere: Roll a die, win $2\times$ the value of the face if it is an even number, or win $1\times$ the value of the face if it is an odd number. How ...
-2
votes
2answers
185 views

Doubles and Trebles [closed]

There are two ponds having lotus flowers - pond A and pond B. The property of the flowers of pond A is such that they get doubled (that is twice) in number every day as compared to previous day (6:00 ...
3
votes
2answers
232 views

Everything leads to “one” number

You get an invitation from an Institute of Mathematics and you are told if you can solve a simple puzzle you can be part of their elite institution. You have to fill the blank. $6 \rightarrow 6$, ...
4
votes
2answers
513 views

Man selling sheep

A man with 90 sheep wants to sell them in a market 30km away from his farm. He went searching for trucks to load his sheep and he found out that every truck can carry 30 sheep at a time, but he will ...
4
votes
3answers
4k views

Solving a Rullo Puzzle

How can I solve in a (relatively easy) way, a Rullo puzzle? (Screenshot below) Rules: Enable or disable a circular number (pink is enabled) in order to make the row or column match the sum on the ...
10
votes
2answers
567 views

What is a Scheming Word™?

In the spirit of the What is a Word™/Phrase™ series started by JLee, a special brand of Phrase™ and Word™ puzzles. If a word conforms to a special rule, I call it a Scheming Word™. Use the examples ...
2
votes
3answers
217 views

Menu subset puzzle creation help

I'm having trouble finding out the best way to create the lists of numbers for the puzzle I'm creating. There are 2 sets of 13 integers (from 1 to 50 inclusive). Call these $A$ and $B$. There exists ...
0
votes
2answers
2k views

Arrange to get sum of 450 when it is added row wise and column wise

I just came across a maths puzzle,where i should get the sum of 9 numbers(multiples of 10) to be 450 both horizontally and vertically in a 9x9 matrix. Picture attached for reference:
5
votes
5answers
2k views

Sum of rows and columns.

In the puzzle, each square is to contain a digit from one to nine. No digit can appear twice in the same row or column. The sums of each row and column are given. Find one of the two solutions. In ...
11
votes
2answers
760 views

Mike's Coin Duplicator

This is my first mathematical puzzle on the site. To be honest, I don't know if this should go to M.SE or here. Any grammatical or backstory edits are welcome, as I realized that my English is not ...
1
vote
2answers
183 views

Monkey with Coins Killing [duplicate]

10 people can share a bucket of coins equally. A monkey steals one coin. The number of coins remaining is therefore 1 less than would allow them to be shared out equally. One person after another ...
2
votes
1answer
341 views

Find the Cell Number, free the Mayor

Last night, the mayor of a small town was kidnapped. 2000 suspects have been brought into the local prison based off eyewitness reports as to what the suspect looked like.One of these 2000 suspects is ...
9
votes
1answer
1k views

What is the rule these numbers follow?

Each row in this grid of numbers follows a specific pattern or rule: ...
3
votes
8answers
963 views

An exercise on the powers without using the logarithm function

One can find on the forums a lot of exercise where the pupils call for help to solve their maths, once I came across an exercise similar to this one: Determine with a simple (non-scientific) ...
2
votes
1answer
191 views

Gambling problem [closed]

I have a Gambling problem. One night I go out and get to a casino and do the usual, get my regular at the bar for only $10 tonight at the bar and head over to the tables, I hit a bit of a bad luck ...
9
votes
2answers
805 views

Simple set of equations

Find 4 equations of the form A [OPERATION] B = C, using the numbers 1-4 and operations $+,-,\times,\div$. Each number must be used once for the A's, once for the B'...
0
votes
3answers
701 views

Math number puzzle/riddle

This not-so-simple puzzle asked by my teacher today, given: $2+2=3$ $4+8=27$ $3+4=8$ So, the answer for: $5+32=?$ I'm new here so pardon my mistakes. Please let me know what you guys thinks ...
5
votes
4answers
674 views

Sticks and stones may break my sum

13 sticks and two stones are laid out as follows: Move three items so the arrangement makes sense. Only the basic functions ×÷-+= are allowed.
1
vote
1answer
157 views

Simple probability game [closed]

You are asked to play a classic shell game with two shells. Each round, a ball is placed under one shell, the shells are rapidly, continuously rearranged for 15 seconds with distraction*, and then ...
3
votes
6answers
44k views

Fill number in missing?

Given options are: A. 13 B. 42 C. 18 D. 30
-7
votes
2answers
766 views

Find the missing number : [closed]

Find the missing number in the following table. Answer Options are: 25 27 32 30
-11
votes
1answer
1k views

find the missing number in the following table

Find the missing number in the following table. Answer Options: 10 12 15 16
3
votes
1answer
575 views

Can you find the pattern?

If the following are true: $4+7+2 = 281435$ $7+3+9 = 212781$ $6+2+7 = 121456$ $2+8+5 = 164036$ Then what would the following equal? $8+4+6\ =\ ?$ Can anybody check my work? I ...
11
votes
2answers
1k views

Lets see how smart Puzzling' stack users really are!

Let's see how smart Puzzling stack users really are! Try to solve the value of x (get angle value). This is related to the http://thinkzone.wlonk.com/MathFun/Triangle.htm , you can search online how ...
1
vote
0answers
52 views

Total number of squares + inside square [duplicate]

How to calculate total number of squares if n×n square box available. Need to calculate 1×1, 2×2 up to n.
5
votes
1answer
280 views

Try to find the hidden letters!

Try to find the hidden letters! Tips: ▲ 1: (1/2)π^2 2: (2πr) + 2r 3: (2πr) + 4r
7
votes
2answers
857 views

Getting to the Root of the Problem

TD:LR - Only the equations and bold question at the bottom are part of the puzzle; the rest is just flufftext. After a long time of searching for the origin of the device I previously posted about, I ...
19
votes
5answers
6k views

How to get 5 from 0,0,0 and 1?

Can you use the digits 0,0,0 and 1 each only once in a mathematical expression for the number 5 using only common mathematical symbols with at least 1 mathematical symbol between each number?
2
votes
4answers
548 views

All locked up and nowhere to turn

While working in your basement, you notice there is a portion of concrete which is not like the rest. It is funny you never noticed it before, but most of the time there was a rug covering it. Tapping ...
9
votes
2answers
365 views

Looking for another partition of 100

The sum of ten, not necessarily different, positive integers is 100. If placed adequately on the vertices of this graph, two of them will be joined by a line if, and only if, they have a common ...
19
votes
11answers
4k views

Add parentheses to make this true

Add parentheses to the following to make a true equation: $10-9\times8-7\times6-5\times4-3\times2-2\times1=1$
3
votes
2answers
421 views

Solve This 'Unknown Operator' Problem

Source If below equations are true, 24 % 6 = 64 35 % 5 = 87 63 % 7 = 99 Then based on similar logic what's the value of below equation ...
15
votes
2answers
921 views

Buttons on an old non-scientific calculator are less sensitive

All 5 numbers are entered in an ascending order. These numbers are in an arithmetic progression. The value of the fifth number, i.e. the largest number, is less than 99. While adding these ...
25
votes
1answer
2k views

How many silver marbles does Paul have?

Peter, Paul and Mary have between them 282 marbles. Though of the three friends, it is Peter who has the most marbles, he is the one with the fewest silver marbles, just the square root of the ...
-8
votes
3answers
4k views

Can you find the missing number in this grid?

Can you find the missing number?
8
votes
2answers
1k views

A mystery partition of 100

Given a multiset (a set with repeated elements allowed) of positive integers, its P-graph is the loopless graph whose vertex set consists of those integers, any two of which are joined by an edge if ...
10
votes
1answer
492 views

Labelling a graph with a partition of 100

Label the vertices of this graph with positive integers (repetitions allowed) whose sum is 100 in such a way that any pair of vertices are joined by an edge if (and only if) they have labels with a ...
15
votes
6answers
4k views

Solve this math puzzle using numbers 0-9

The numbers used can only be from 0-9 and can't be used twice. The unused digit needs to be less than 6.
15
votes
1answer
1k views

Rybo switched the calculator keys!

I'm Dave. In revenge for my calculator key-switching prank, Rybo has performed a similar prank on me! My calculator has the usual number keys, and keys for the usual four arithmetic operations: ...
2
votes
5answers
955 views

Make 12 with 1, 5, 19, 10

How can you make the number 12 with just the numbers 1,5,19,10? You can only use each number once, and can only use subtraction addition multiplication and division.
-1
votes
1answer
1k views

How to solve Rubik's Cube using mathematical formulas? [closed]

I am trying to solve Rubik's Cube, but it took one month for me when I started. Are there any mathematical formulas, rules and tips for solving Rubik's Cube in less time (i.e. minutes)?