Questions tagged [calculation-puzzle]

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

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3
votes
1answer
2k views

How to approach “pattern finding ” questions?

I've seen a lot of these types of puzzles in IQ tests, quizzes of various sorts, and I have never been able to figure out how to solve them. These generally involve two or more sets of geometrical ...
3
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1answer
689 views

Decrypt this Cryptogram: cs.aoa.daso

The encrypted text is: (. is a letter separator and <br> or line break is a word separator) cs.aoa.dasocs.fsi.rxhgs.al....
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4answers
475 views

What is the solution of the last operation?

Each symbol represents a number between 0 and 9. You need found the number which is the solution to the last operation. The two triangles in the first operation and the triangle and the rectangle of ...
3
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1answer
1k views

The puzzle is to decrypt this encrypted text. (Cryptograms)

The Encrypted text is: 7q7f 93d4 6s03 8aua 3pn9 73wu 9l2l a1wx 8u52 9tld 6fhc axfx 8kn4 628q 4abk 314d 255s 5o5b 9cc1 5904 4sja aa1r 7fai apsw 80ph ai09 ejbs I am currently (at the time of posting ...
0
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2answers
462 views

Finish The Pattern #3 [closed]

Given this pattern: 0, 1, 0, 2, 2, 2, 3, 4, 5, 6, 6, $n$ Find the next item at $n$ Pattern/sequence explanation required
1
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1answer
1k views

Finish The Pattern #2

Given a pattern: 0, 1, 2, 0.5, 2, 3, 5, 1, 2, 0, 2, 1, 4, 2, 3, $n$ Find the next item at $n$. Pattern/sequence explanation required
0
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1answer
2k views

Finish The Pattern #1 [closed]

Given a pattern: 12, 22, 35, 68, 15, 28, 31, $n$ Find the next item at $n$. Pattern/sequence explanation required
4
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2answers
1k views

What is the maximum number of cities that can be destroyed?

As a commander of an army battalion, you have to plan the attack on some enemy cities which are connected by road-network. Before starting the attack, you have information about all the cities and ...
-2
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1answer
2k views

Calculating row number and column number [closed]

What I am trying to do is calculate the row and column of which an id is in. For example I have the grid 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 As you ...
4
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5answers
1k views

The game of Sevens

There is a popular game, named Four fours, where you have to find the shortest mathematical expression for every number from $1$ to $n$, using only the number $4$ and some operators. My variant of ...
13
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1answer
1k views

A Quote from what Movie?

Heads up: It's possible to solve this puzzle without writing computer code, but it is intended to be solved with computer help. This is a 2-stage puzzle. Stage 1: Calculation Puzzle Rules: 1. You ...
2
votes
1answer
250 views

How Much Bread For Her Budget? [closed]

A woman is looking through a store and sees a sign for 2 dollar bread saying "For every 10 loaves you buy, you get each for only 1.9 dollars!" A pretty strange deal, but she decides to take it. If ...
0
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2answers
265 views

What is my room?

You are heading to your hotel room but forget your room number. Try to check the key card but the digits are blurred You call to hotel desk info and a nerdy bell boy tell you: Your room have 4 ...
54
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13answers
11k views

Making π from 1 2 3 4 5 6 7 8 9

There have been two other questions here and here that are similar to this one, but this changes the rules up a little. Your job is to approximate $\pi$ using the sequence of digits (in order): 1 2 ...
7
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2answers
461 views

Bitwise multiplication

Mr. EG has come up with a great coding scheme for (non-negative) integers in binary. To show off his creation, he demonstrates the following multiplications: ...
14
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12answers
263k views

1 2 3 4 5 6 7 8 9 = 1

This question inspired me to write the same puzzle but instead replace the "= 100" with "= 1" with similar requirements and restrictions. What is the expression with the fewest number of operators ...
-3
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1answer
2k views

How many would die after E slightly pushes the structure in front of him? [closed]

As you can see in the picture, there are 5 people A, B, C, D, E. E is going to slightly push the circular structure so that the initial velocity of the structure on the inclined plane would be zero. ...
43
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10answers
142k views

1 2 3 4 5 6 7 8 9 = 100

The sequence of numbers $1\ 2\ 3\ 4\ 5\ 6\ 7\ 8\ 9$ has the property that you can insert mathematical operators in between the numbers from $1$ to $9$ and make the expression evaluate to 100. For ...
10
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4answers
1k views

A number and its square

Find a four-digit number which is equal to the four least significant (rightmost) digits of its own square.
11
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3answers
2k views

A self-referring number

Find a ten-digit number with the number of zeros in it as the most significant (leftmost) digit, the number of ones as the second most significant digit etc.
5
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3answers
5k views

Create integers from 1 to 50 using only one integer and other functions

Your task is to create all the integers from 1 to 50 (inclusive) using only a single integer $x$ and... Addition ($+$), Subtraction($-$), Multiplication($\times$), and Division($\div$) Floor($\left \...
7
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2answers
727 views

Evaluate the nested square roots

Evaluate the following expression to 4 decimal places: $$\sqrt{1+2\sqrt{1+2\sqrt{1+\dots+2\sqrt{1+2\sqrt{2015}}}}}$$ where the number of square roots in the expression is exactly 2015. As per the ...
3
votes
1answer
277 views

Can Blaine distribute 15 money bags fairly?

Backstory Blaine Fairway, a senior manager at CurrFlow Industries, Inc., has been personally accepting large rebates for multi-billion-dollar purchases from certain manufacturers for years, although ...
3
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1answer
812 views

Calculate a mystery number: Add the number of United States …

You start with a mystery number from 1 to 100000. Add the number of United States, Divide by a quarter incense by sounding it out, Subtract the month of Hallowe'en, Take the square root of your ...
-3
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1answer
258 views

Arithmetic/Knowledge Step-By-Step Number Puzzle! (What Is The Final Answer?) [closed]

Start with the number of U.S. ounces in a U.S. gallon. Subtract the atomic number for Samarium. Add the amount of days in February on a leap year. Multiply this by 6 factorial. Divide this by pi ...
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3answers
2k views

Vegas Street Magician Math Trick

I went walking with a friend of mine in Las Vegas last week. We turned a corner and saw a street magician doing some tricks for a crowd of 12-15 people. In most of his tricks, the magician would make ...
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0answers
203 views

Shooting an invisible rabbit [duplicate]

An invisible rabbit sits on one of the posts of an infinite fence. A local farmer cannot stand this fact and wants to shoot the rabbit down*. Every time the farmer shoots her gun, the rabbit jumps to ...
2
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1answer
3k views

How many watermelons left with Mr. Bean?

Mr. Bean leaves from place $A$ with 3 sacks that each contains 30 watermelons. He comes across 30 tolls till he reaches place $B$. At every toll, Mr. Bean has to give 1 watermelon as toll for each non-...
1
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6answers
537 views

How many Pigeons are there?

There are pigeons sitting in a queue. The first one said, "There are 4 pigeons behind me." The last one said, "There are 4 pigeons in front of me." The middle one (or, one of middle ones) said, "There ...
2
votes
1answer
216 views

Dancing, dancing, dancing

My friend Kim told me: Last week I went to an afternoon party. I was the last guest to arrive. I looked around and counted (not including myself) altogether 14 grown-ups and 17 children. ...
3
votes
4answers
702 views

The 2015th question on Puzzling SE

At the time of posting, this was the 2015th question posted on Puzzling Stack Exchange, in the year 2015. Take the number of multiples of 5 among the numbers featured in this puzzle. Multiply it by ...
5
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4answers
644 views

A tour of 36 cities

Each of 4 people is touring 36 cities separately. Each of the 36 squares in the illustration below represents a city. To make the answers shorter, each city has been given a 1-character name, from A-Z,...
8
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3answers
3k views

Where has Jones lost 1 Rs?

Jack and Jones are brothers and they both sell apples for living. Jack sells 2 apples for 1 Rs and Jones sells 3 apples for 1 Rs. They each have 30 apples. Hence, Jack earns 15 Rs a day while Jones ...
30
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1answer
2k views

Computation without a computer

In the number $(1+\sqrt{3})^{2015}$, what is the 224th digit after the decimal point? You may NOT use a calculator, computer, or any electronic aid to answer this question. Only pen(cil), paper, and ...
8
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2answers
1k views

$\tau$ is greatest! $\tau$ is all (from 1 to 20)

(This is basically an extension of $\pi$ Day puzzle one to twenty) $\tau$ is greater than $\pi$ and $\tau>\pi$. Create the numbers from $1$ to $20$ using only: Tau ($\tau$, equivalent to $2\pi$) ...
14
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3answers
2k views

How old is the ship of Theseus?

The ship of Theseus consists of n parts. The first part needs to be replaced every day, the second part every second day, the third part every three days and so on. Theseus is concerned that ...
8
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3answers
1k views

$\pi$ Day puzzle one to twenty

Create the numbers from 1 to 20 Using $\pi$ Normal arithmetic operation $+ - * /$ Square root $\surd$ Exponential $(X^Y)$ Negative() minus sign $-$ Floor() function, express between $[ x ]$ $[ ...
7
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3answers
1k views

3x3 “Magic Square” of Prime Numbers — Part II

Glad to know the previous puzzle, which was the first puzzle I posted in Puzzling, was warmly welcomed (Thank you!), and an optimal solution was found. Inspired by the comments there, here is the ...
2
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1answer
390 views

What will be the price of the dog? [closed]

Two men had a certain number of camels, and sold those camels. The price of each camel was equal to the total number of camels they owned initially. They then bought a certain number of goats for that ...
20
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6answers
6k views

3x3 “Magic Square” of Prime Numbers

During the thinking and analysis of some mathematical problems, I came up with this puzzle: Just like any magic square, one has to fill in $9$ different numbers $P_1, P_2, \dots P_9$ to a $3 \times 3$...
12
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3answers
745 views

Replace each ? in the expression with a digit or operator

In the following expression, replace each ? with either a digit or an operator: 8?5+??5-9?+3 so that it can evaluate to: <...
8
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2answers
2k views

What is the next term in the sequence?

The first term is f(0), the last term is f(2000): 0,0,0,0,1,0,1,0,2,1,1,0,2,0,1,1,3,0,2,0,2,1,1,0,3,1,1,2,2,0,2,0,4,1,1,1,3,0,1,1,5,0,2,0,2,2,1,0,4,1,2,1,2,0,3,1,5,1,1,0,3,0,1,2,6,1,2,0,2,1,2,0,4,0,1,...
8
votes
1answer
657 views

A dollar, a penny, there's no difference

Sam is a gluttonous kid, so he decides to buy a colorful lollipop at the price of 1$ (one dollar) in the nearest candy store. Though, he realizes that he can't afford it as his budget is just 1¢ (a ...
11
votes
2answers
877 views

Vladimir and his motorbike

Vladimir wants to take his two daughters to their Dacha (weekend house) which is located 66 kilometers away from their home. Vladimir's motorbike has a maximum speed of 50 kilometers per hour; with ...
19
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26answers
11k views

Building a 2 mile runway on a 1x1 mile island [closed]

You have a 1-mile long x 1-mile wide island. When taking off from a flat runway, a plane requires a runway of minimum length 2 ...
-2
votes
1answer
265 views

There's an ARG I've been working on, and I'm stuck on this puzzle part II

Hees the first one incase you havent seen it. There's an ARG I've been working on, and I'm stuck on this puzzle So from that we got our password for this "problem" however we havent ...
7
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4answers
2k views

What is my friend's PIN?

Just a fun Puzzle: My (fictive) friend told me his PIN: "My PIN is the highest 4 digit number that has the highest sum of unique differences." He explained: "my PIN consists of 4 numbers A B C D. ...
24
votes
4answers
10k views

The largest integer made of 1,2,3,4

What is the largest integer $A$ that can be produced from the four digits $1,2,3,4$ subject to the following rules? Each of the digits $1,2,3,4$ is used exactly once. Juxtaposition of digits is ...
50
votes
3answers
6k views

Where is Jennifer's husband?

Jennifer is 21 years older than her son Douglas. 6 years from now, Jennifer will be 5 times as old as Douglas. Question: Where is Jennifer's husband most likely to be right now?
3
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6answers
2k views

Alignment of planets that orbit at different speeds [closed]

If a planet completes its circle around the sun in 120 years and another planet in 70 years then when will they come in a straight line as if they are now?