# Questions tagged [calculation-puzzle]

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

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### How do you get 23 using the numbers 1, 2, 3 and 5?

You can only use Addition, Subtraction, Multiplication, Division. This is for a math project for my daughter. You can only use the numbers once and all numbers do not need to be used.
4k views

### Doomsday will occur in the year with a triple blue moon

A group of men are working and counting on a very serious prophecy, which says "Doomsday will occur in the year with a triple blue moon". When will Doomsday occur? Note : A blue moon is a second ...
149 views

### Instructing People to use minnimum time for a task? [duplicate]

There are 5 persons standing on a side of tunnel. A, B, C, D, E Each takes 10, 30, 15, 20, 29 minutes to cross tunnel ...
230 views

### Interesting card combinations [closed]

In a normal pack of playing cards (without jokers), the probabilities of the following events are the same: (1) Drawing a set of 4 different cards (irrespective of its color and suit) - let us call ...
3k views

### Upside-Down Number Problem

These are numbers that can also be read upside down as the same number, or different number: 0, 1, 6, 8, 9, 10, 11, 16, 18, so on. Each number can only be used once. Using these numbers, try to get ...
153 views

### Redesign an analog clock [closed]

An odd mathematician and engineer decides to redesign an analog clock. It now has 2 periods of 10 hours, each hour is divided ...
448 views

### Boggling googling

I'm a number for you to evaluate, Googling 'me' gives the drop off the Empire State, Though the great Google finds no results for me, I'm just a pure integer value you'll see. What number am ...
616 views

### What is the next number in the following sequence?

1, 6, 5, 3, 4, 1, 2, 2, ? Hint: the task is pattern recognition using basic mathematical operations.
656 views

### mystery operations

1.  3 __ 2 __ 36 __ 4  =  67 2.  3 __ 2 __ 36 __ 4  =  150 3.  3 __ 2 __ 36 __ 4  =  176 4.  3 __ 2 __ 36 __ 4  =  71 Fill in the blanks ...
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 ...
2k 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 ...
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 ...
251 views

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'...
734 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 ...
676 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.
158 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 ...
45k views

### Fill number in missing?

Given options are: A. 13 B. 42 C. 18 D. 30
767 views

### Find the missing number : [closed]

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

### find the missing number in the following table

Find the missing number in the following table. Answer Options: 10 12 15 16
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 ...
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 ...
53 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.
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
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 ...
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?
550 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 ...
366 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 ...
5k views

### Add parentheses to make this true

Add parentheses to the following to make a true equation: $10-9\times8-7\times6-5\times4-3\times2-2\times1=1$
434 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 ...