Questions tagged [calculation-puzzle]

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

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5
votes
3answers
362 views

Monkey on a Flagpole [closed]

A 3 feet tall, hungry monkey is trying a reach a magical banana placed on top of a flagpole. The flagpole is 25 feet in height and is slippery to grasp. Every Odd numbered Jump, the monkey climbs 3 ...
15
votes
2answers
1k views

Ernie and the Unexpectedly Exposed PIN

I dropped in on Ernie a few days ago. As I pushed open the door to his workshop I could hear a clanking, hissing noise and then saw Ernie emerging from a great clouds of steam, his face blackened with ...
8
votes
1answer
539 views

What's Jeremy's Encryption Algorithm?

As a result of their solutions to this puzzle, store owner Jeremy promoted both Cerberus and Quark to top managerial positions. Soon after starting their new roles, they were somewhat surprised when ...
4
votes
4answers
2k views

An Hourglass Puzzle

This puzzle follows from the well known sand timer puzzles: A Sand Timer Challenge http://www.crazyforcode.com/sand-timer-puzzle/ http://www.cut-the-knot.org/hg_solution.shtml Warmup: You are given a ...
11
votes
1answer
1k views

What is a Donut Phrase™?

Bwahaha! You're not the only one who can make these puzzles, JLee! (this is an unofficial continuation of JLee's [in]famous Word/Phrase puzzles) The following phrases of varying lengths follow a ...
3
votes
5answers
572 views

Chile to Singapore

Hey guys, I've been into brainteasers since I was little and recently decided to make a puzzle-related website. I figured that this will be the best place to share some of my problems and see if they ...
2
votes
1answer
204 views

Depressed Numbers [duplicate]

$12 = 0$ $1234 = 1$ $123456 = 2$ $12345678 = 4$ $369 = 2$ $248 = 3$ $2 = 0$ $3 = 0$ $5 = 0$ $7 = 0$ $11 = 0$ $13 = 0$ What does: $123456789 = ?$ Why? Hopefully isn't too hard, please ask if you ...
3
votes
0answers
111 views

Minimum number of telephone calls needed to exchange information [duplicate]

There are 16 secret agents who each know a different piece of secret information. They can telephone each other and exchange all the information they know. After the telephone call, they both know ...
19
votes
5answers
2k views

What is a Surpassing Phrase™?

If a phrase conforms to a certain rule, I call it a Surpassing Phrase™. Use the examples below to find the rule. Some details to save you time: 1. Font doesn't matter. 2. The number of words ...
12
votes
1answer
818 views

Ernie and the Bubbles of Lucretia

"So, what do you know about milking spiders?", asked Ernie as he passed a fresh cup of coffee to me. Good grief!, I thought and gave an involuntary shudder as I glanced at the milk jug sitting ...
8
votes
3answers
2k views

Baumic Numbers!

I have a class of numbers; this class of numbers contains a certain number if and only if it is baumic. The following are baumic numbers: 1, 6, 9, 15, 20, 21, 30, 33, 39, 45, 50, 51, 56, 57, 69, 70,...
5
votes
2answers
8k 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 ...
-1
votes
1answer
1k views

Cryptic Woman and a Confused Census-Taker [duplicate]

I recently found a card on which there were two puzzles, both of which have me stumped; I want to spend a little more time on the other puzzle, but here is one that stumps me: no 65 A census-...
7
votes
1answer
564 views

MC Frontalot 80085

MC Frontalot is a musician, and one of his songs is a word problem that seems to me like it belongs here. If you want to listen to it instead of just reading the lyrics, a quick video search of "MC ...
0
votes
3answers
10k views

A Water Jug Problem [duplicate]

Suppose you are given two jugs: a 4-gallon one and 3-gallon one, and neither has any markings on it. You have a pump that can be used to fill the jugs with water. What do you do so that exactly 2 ...
14
votes
3answers
2k views

The Pie-Maker's Son

Preface: There's a lot of background story here. Most of it is just for fun but there are definitely clues sprinkled throughout. If you want the strict puzzle, skip on down to the bottom. For many ...
-4
votes
1answer
857 views

Using the digits 2, 3, 4 make an expression for 30

Write an expression using exactly one 2, exactly one 3, and exactly one 4 to make 30. For each problem, you must use all three of these: Division Factorials (just for regular factorial use, no ...
-5
votes
2answers
1k views

Make 24 and 30 using the digits 3 and 4

First, write an expression using exactly one 3 and exactly one 4 to make 24. Second, write an expression using exactly one 3 and exactly one 4 to make 30. Math You Can Use for each problem: ...
0
votes
3answers
477 views

What happened to the missing £10? [duplicate]

I have come across a puzzle, which makes no sense. Does anyone know the answer to the below? You and two friends go on holiday. When checking out, the total bill comes to £300. You pay the bill ...
7
votes
4answers
2k views

A Threes Of Cake

This question is similar to my other question Twos For Thought, which arguably was a better pun but I decided to recreate the question, except with threes! How many threes do you need to get to the ...
4
votes
4answers
560 views

Twos For Thought

How many twos do you need to get to the number $100$ exactly? Example: $22+22+22+22+2^2+2^2+2^2$ This example method uses 14 twos and is obviously not ideal. Can you find a way that uses the least ...
0
votes
3answers
1k views

Find a number that is 9 times bigger than total of its digits?

Find a number $X$ that is 9 times bigger than the total of its digits: for example if $X=abc$, then $X=9*(a+b+c)$. I don't know the number of digits; it could be 3 or 2 or more.
4
votes
2answers
1k views

Unique Licence Plates

Note: This is a Mathematical puzzle, not a Mathematical problem. Although the answer could be solved with mathematics, lots of problems on Puzzling SE could be solved with mathematics, and the problem ...
7
votes
3answers
687 views

Four Rings & Seven Digits

Replace a to f with the numbers 1 to 2 & 4 to 7, so that the sum inside each ring is the same. There is only one solution!
19
votes
16answers
5k views

You're invited! Now what?

(semi-interactive puzzle) BRIIING! BRIIING! BRIIING! You wake up with a start. It's 6:30... already!? Darn. You roll slowly out of bed, preparing for the day ...
9
votes
6answers
2k views

Who's the oldest?

Albert, Brian and Charles are brothers with different ages. Albert has twice the age Brian will have when Charles has twice the age Albert has now. Who's the oldest?
10
votes
8answers
2k views

The 8 year old politician?

If I am on top politically, I am right, but if I am on top of being not in violation, I am wrong. If I am above 8, I am wrong, but if I am low on being not in violation, I am forever. I cannot be ...
6
votes
4answers
1k views

This is not math. This is war!

I have two operators! They are very close, brothers, actually! Though they are like each other's negative.They are named $\mathfrak{C}^+$ and $\mathfrak{C}^-$. No one knows what's going on in their ...
5
votes
1answer
415 views

Loser-Winner-Loser

3 players start a game in which one of the players wins and the other 2 lose. Each loser has to pay the winner twice the amount he (the winner) had when (each) game started. After 3 consecutive ...
9
votes
1answer
3k views

Upside-down numbers differing by 78633

When I acquired my Mercedes-Benz car in Germany, the first thing I had to do was to get a license plate. The plate I got had a peculiar number on it. It consisted of 5 different numbers and by mistake ...
10
votes
3answers
638 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.
20
votes
2answers
2k views

SPEND LESS MONEY alphametic

The well-known verbal arithmetic problem S E N D + M O R E ----------- M O N E Y explains (or at least it did the first time I knew about it) the story ...
12
votes
1answer
1k views

Diabolical dice!

I have two 6-sided dice which between them have 12 different numbers, but some of the numbers are hard to tell apart because one is the same as the other upside down (like $89$ and $68$). I throw the ...
-2
votes
1answer
232 views

how long does it take to fill cistern (0.24 of cistern)? [closed]

We have a cistern (reservoir). This storage has 2 income faucet (2 interval water) & 1 outgo faucet(1 out pass). By one of the interval pass which in bigger it takes 1 hour to fill storage & ...
4
votes
5answers
5k views

Solving This Vietnamese Mathematical Puzzle for 8-Year-Old Children

Sudoku friends, this one's for you. This maths puzzle was set for eight-year-old students in Bao Loc, Vietnam, and they have actually been able to solve the puzzle. Even some people with doctorate in ...
5
votes
2answers
481 views

Solve the Unconventional Equality

Can you solve the following equality? $432 = 915$ $944 = 850$ $211 = 403$ $837 = 927$ $735 =\: ???$ Additional numbers: $734 = 5100$ $736 = 736$ $835 = 741$ HINT 1: There are ...
10
votes
1answer
1k views

Dissection of the number-grid (addition/subtraction)

This is the first - presumably simplest - puzzle of an intended series of numerical dissection puzzles. The goal is to dissect the 15 x 11 number-grid below into exactly 17 rectangular sub-grids. ...
-2
votes
2answers
288 views

You and your “Princess” [closed]

You are an Archer and participating in a tournament. You need to hit the Bull's Eye to win the tournament and the Prize (a big fat pig called "Princess". Wodehouse Anyone?). You love big fat pigs and ...
-3
votes
6answers
332 views

Will both workers count the same number? [closed]

Original problem Lets assume that we hire two persons to count passers-by for an hour. One is told to stand still at one spot on the sidewalk. The other one is told to walk 20 meters up and down the ...
1
vote
4answers
237 views

More males or females [duplicate]

In a society (presumably Asian) where sons are preferred over daughters, couples adopt the following heuristic when reproducing: If the new-born is a daughter, try for a new child When the couple ...
21
votes
1answer
1k views

A diabolical puzzle: Hector + Tisiphone =?

Homer + Ovid = Paris Ulysses + Julius Caesar = Nimrod Guy de Montfort - Cleopatra = Medusa Epicurus - Pluto = Dido Hector + Tisiphone = ?
13
votes
4answers
2k views

ALIEN Counting System

When humans finally came across some aliens, living below the Martian crust, the strangest point was that the myth of symmetry was broken. Humans had assumed that all intelligent life forms would be ...
0
votes
0answers
74 views

Freedom from the guarded island [duplicate]

You, a well-known submarinist criminal, are taken prisoner in a perfectly circular island, surrounded by water. You stand in the center of the island, with the submarinism equipment (don't worry ...
-2
votes
5answers
531 views

Form a number using some numbers and mathematical operations

Using 2,3,4,5,6,7 and basic mathematical operations form the number 1088. Every digit must be used exactly once (neither zero nor greater than one times). Concatenation of digits (such as 53) is not ...
-4
votes
2answers
212 views

Using numbers form a number

Using 7,8,9 and basic mathematical operations form the number 327600. Use every digit exactly once. Note: Allowed Operations: $+,-,/,*, {}^{\displaystyle\large\hat{}} ,!,\sqrt{}$
1
vote
1answer
455 views

Slot Machine Challenge

Karen owns a restaurant/bar. She wants to attract more customers, and is building her own custom slot machine game, which she can use to give away free drinks or prizes. The more a customer spends, ...
5
votes
1answer
304 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 ...
0
votes
2answers
344 views

Race of the century

Four drivers face off in the race of the century. The path of the race follows this layout: 100 KM road with a sharp turn every 5 KM 50 KM straight road 50 KM straight river 40 KM upstream river 40 ...
19
votes
2answers
2k views

Ernie and the Alien Invasion

Yesterday I dropped in on Ernie to show off my new j-watch. Ernie wouldn't be impressed by instant wrist-mounted access to social media sites like me-tube, tweeter and farce-book so I thought I would ...
3
votes
7answers
524 views

The result for the following pattern

What will come at the "?" Follow the pattern. A + B = E B - A = C A + D = Q D - B = L then A + C - B = ?