Questions tagged [calculation-puzzle]

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

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0answers
43 views

Sequence puzzle in rows [duplicate]

The below is a number puzzle. It should be read left to right, top to bottom. Question 1: What is the next two rows of numbers? Question 2: How was this reached?
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6answers
2k views

Through which number we can remove the question mark?

I'm trying to solve this puzzle but so much confused and can't understand even.Please help me to solve this puzzle and also explain briefly.
5
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1answer
131 views

21sums - more constraints

My initial question had lots of answers, as we can practically choose the middle square to be anything we want, and work outwards to the exterior edges, with the corners providing the flexibility ...
10
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1answer
2k views

Which two numbers replaces the question mark?

I was solving some number puzzles. I am finding difficulty in solving this puzzle: which two numbers will replace the question marks? I need answer with explanation.
5
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5answers
4k views

A Set of Water Jug Challenges

You've probably heard about challenges with water jugs, so why not try a few? Use 3- and 5- liter jugs to get 4 liters. Use 5- and 7- liter jugs to get 4 liters. This one's different. How many ...
7
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2answers
382 views

Fuzzy the Fuzzball

Fuzzy the fuzzball was very sad. He had lost his fuzz. Everyone knew if you lost your Fuzz you could no longer be a fuzzball. Fuzzy went to this friend Frizzy and shared his dilemma. "Don't worry, ...
7
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2answers
958 views

What date can it be?

To save money, a meticulous person had a oddly unique way of splurging money. Each day the person would splurge an amount equal to the month-digits + day dollars. So for the first of April it would ...
10
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3answers
651 views

Finding the Dr. Bronowski's number

All credit for this problem goes to Dr. J. Bronowski. Find the least positive integer such that moving the leading digit to the end produces a new integer one and a half times the original.
14
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11answers
22k views

Find out the correct number

Find out the correct number to replace the question mark. Source: Beijing Aidi International School summer test (2018-08-21). Author: 坦途国际教育
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2answers
9k views

Finding Day Puzzles

When the day after tomorrow becomes yesterday, the day which would then be today will be as far from Sunday as the day which is yesterday when it's two days after that day's tomorrow. What day of the ...
5
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1answer
559 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 ...
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3answers
513 views

Simple Math Problem #3

Previous Puzzles(Not linked to this one): Simple Math Problem #1 and Simple Math Problem #2 Prove the equation: $-6439832+ = 9$ $-$ and $+$ are there just to tell that you can use only these two ...
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6answers
700 views

Pizzle - Will you ever show up, Rick?

NB: Pizzle = Puzzle + Riddle Chapter 1: Let's start (solved in comments) You can see me, but you can not catch me I'm lightweight, but I could lift you up easily Chapter 2: The First Piece (...
4
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5answers
437 views

Time-Motion puzzle

Time and Motion studies are well established. Here is an easy question: It takes 8 men 6 months to build 2 houses at a cost of $50,000. It takes 10 men 5 months to build 3 houses at a cost of ...
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5answers
3k views

All clock hands at equal degrees from each other

My dad once asked me: At what time will the second hand, minute hand, and hour hand on an analog clock all be $120^{\circ}$ from each other? It's a simple question, but I thought it was a fun ...
5
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1answer
466 views

Solve this puzzle. I created for my friend for FUN :)

My friend is very good at puzzles. so i thought of creating one by myself and try to see if he can solve. Finally I succeeded and he gave up. Interested people can try. Hint: use all four arithmetic ...
14
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2answers
19k views

What's the fewest weights you need to balance any weight from 1 to 40 pounds?

Suppose you want to create a set of weights so that any object with an integer weight from 1 to 40 pounds can be balanced on a two-sided scale by placing a certain combination of these weights onto ...
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1answer
241 views

What is the value of X?

24 6 63 132 4 14 23 x 17 The answer is either : 21, 14, 3 or 2
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1answer
304 views

M professors and N dishes

Suppose 'M' number of professors have to guess 'N' number of dishes on a roulette menu offered by a restaurant. This restaurant has a special "roulette menu" with N items, in which you choose a menu ...
2
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6answers
280 views

A Maximising Puzzle Gift for my Girlfriend and I's 28th month Anniversary

The 28th of december 2018 will exactly be the 28th month since I date my fabulous girlfriend, by this time she'll be 18 years old. Here's a puzzle I'll give her this day : Classical part Maximize $...
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2answers
3k views

N pirates steal their share of bananas to the benefit of a monkey

The following is a type of logic / math puzzle I've yet to see on this site. I feel it belongs because the kernel of this problem can be reworked into other puzzles. $N$ pirates find themselves ...
6
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8answers
548 views

Make $1,\dots,15$ using $3, 9, 9, 9$

This was inspired by many puzzles that use three/four numbers to create other numbers. I chose these numbers in particular because of this post. Can you find a way to make all the natural numbers ...
2
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1answer
174 views

What is the expected result? [duplicate]

I found the following puzzle through social media websites, What is the expected result? It seems to be easy. But, it needs concentration.
3
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2answers
755 views

make this sum using only +

A bit of a speed question this, first correct answer gets the check. Although you are allowed to use computers, it might be quicker not to. By placing only $+$ signs between some of the numbers on the ...
14
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6answers
3k views

Use 2 0 1 and 8 to make 67

Use $2$ $0$ $1 $ and $8$ to make the number $67$ RULES You must use all 4 digits. Only the digits 2, 0, 1, and 8 can be used. You can make multi-digit numbers out of the numbers. Examples: 20, 82, ...
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2answers
900 views

Use 2, 0, 1 and 8 to make 71

Use all and only the digits $2,0,1,8$ once each to make the number $71$. Allowed operations; anything not on this list is banned: $+,-,\times,\div, ()$ (parentheses and/or choose function) ...
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2answers
181 views

Use math symbols to produce 6 [duplicate]

How can we get (6) from these numbers? $2$ $2$ $2 = 6$ $3$ $3$ $3 = 6$ $4$ $4$ $4 = 6$ $5$ $5$ $5 = 6$ $6$ $6$ $6 = 6$ $7$ $7$ $7 = 6$ $8$ $8$ $8 = 6$ $9$ $9$ $9 = 6$ $12$ $12$...
15
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4answers
4k views

For how long did Lisa walk?

Lisa gets picked up from work by her husband at exactly 4 pm every day. One day Lisa finished work half an hour earlier and started walking to meet up with her husband. She met her husband on the way, ...
4
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5answers
2k views

What is her real age? [closed]

He : What is your age? She : 35 years old, ignoring the intervening Saturdays and Sundays. What is her real age?
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2answers
2k views

Number Series - 1,20,171

$1,20,171,?,9625,57756,288775$ Please find the missing number in the series. I have already tried with squares, cubes and progressions but couldn't find the problem.
4
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2answers
4k views

Find the missing number (triangle)

Find the missing number (triangle) Options: 9 8 7 10 Please write the logic also.
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3answers
88 views

Puzzle #1: Love In the Air

A couple that were just engaged decided to have their wedding in a hot air balloon. The biggest problem that the couple has is how many guests that they can invite. There are three different types of ...
3
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2answers
84 views

Puzzle #2: Prosecutor's Pathway

This one prosecutor has a very busy schedule. However, although his business can get busy, he is a lawyer faithful to his job, which is why he spends some weekend time at his private law firm. Since ...
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2answers
387 views

A Secret Math Society

I was about to try to join the famous Math club at my school when I stopped to hear my classmates doing the same. I didn't know that newcomers had to take a simple test to be qualified until my they ...
4
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1answer
183 views

Another pattern puzzle with a twist…well, not quite so

What are the next two terms of the following crazy sequence: I, h, 6, 9l, 52, 9E, 6h, __, __ ?
2
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2answers
818 views

Which switch is faulty?

How to solve this puzzle? This puzzle is taken from the book The Ultimate IQ Test Book by Philip Carter and Ken Russell.
4
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1answer
258 views

The wine paradoxon

You're a fellow salesman who happens to have to sell a barrel full of wine. The barrel has a capacity of 5 Litres. Unfortunately, your apprentice is a wine lover and steals some wine each night, ...
5
votes
1answer
314 views

How to choose the next board in the 8-puzzle?

I hope to have your help to solve the problem I am facing. I'm trying to make an 8-puzzle solver but I'm in doubt about how to select the next board, from the one they have already given me. Below I ...
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1answer
115 views

double the stone puzzle

Story: I've x number of stones. On my way, I will cross three wells. When I reach a well, then I will throw y number of stones ...
3
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1answer
546 views

I have more than one face, but I have no eyes. I roll out of hand during multiple tries

Riddle me this: I have more than one face, but I have no eyes. I roll out of hand during multiple tries. I very much often do not roll alone; I have a partner, who like myself, ...
5
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4answers
537 views

New Arithmetic Operator?

So my British friend proposed a new operator, but he wouldn't tell me how it works. He told me if I could figure it out then I could know. He's not very nice. Anyway, help me figure it out? 1 🎫 1 =...
8
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5answers
1k views

Streets Puzzle and Positions

The diagram below shows the street map of a city. If three police officers are to be positioned at street corners so that any point on any street can be seen by at least one officer, what are the ...
15
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9answers
5k views

Is this sequence that hard?

I published a sequence that seems difficult to the general public, so I've thought of posting it here. It has a very simple logic (language independent). Can you figure out the next number?
8
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3answers
566 views

Order matters twice

Mr. Accurado, a keen and sharp eyed professional thought of starting his special assignment at few seconds past midnight. However due to a distraction- which lasted for less than a minute - he could ...
2
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6answers
1k views

How cold is too cold? [closed]

On a day during a severe winter, somewhere in cold countries, I watched a weather report on a television. The report showed that on that particular day the temperature was 0° ....but due to some ...
8
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1answer
653 views

Magic Square Puzzle

Construct a 5x5 magic square. 1- Numbers from 1 to 21 can be used. 2- Sum should be 55 (Horizontally, Vertically and Diagonally) 3- Any 4 digits from 1 to 21 can be repeated only once. 4- The Numbers ...
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5answers
2k views

Making Things Difficult

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Factoring the Time Think fast! If you're looking for meaning, these clocks have some for you. Keyboards are Disgusting Gunky ...
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0answers
68 views

3 Horses out of 25 Horses [duplicate]

You've got 25 horses and you can host races in groups of 5. You don't have a stopwatch, obviously. Then what should be the minimum number of races that you should be conducting so as to ascertain the ...
9
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2answers
496 views

How old are Charlie's pets?

Last year at a picnic, Charlie told Julie's daughter the sum and the product of the ages of his dog and two cats, but she guessed the ages incorrectly. This year, he gave Steve's daughter the same ...
5
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1answer
331 views

Permutation At A Railway Track

Engines numbered 1, 2, ..., n are on the line at the left, and it is desired to rearrange(permute) the cars as they leave on the right-hand track. An engine that is on the spur track can be left there ...