# Questions tagged [mathematics]

A puzzle strongly related to mathematical facts and objects, or whose solution needs serious mathematical arguments. General mathematics questions are off-topic but can be asked on Mathematics Stack Exchange.

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### The Most Powerful Number

A power-full number is defined as a number with $n$ amount of non-zero digits $D_x$. The number takes the form $D_n$&$...$&$D_2$&$D_1$. The digits in a power-full number satisfies the rule ...
2answers
151 views

### Hexagon vs Harry Houdini…Round 1…How did Harry do? Let us Find out

$Given:$ Harry Houdini is Mental Math Magician and top Math Wizard at Hexon..one of the top cryptographic companies in the world. They have deployed Passwordless super smart secret system to ...
2answers
95 views

### Math quiz from a book [closed]

A student took some exams. The arithmetical average of his grades is 25. He takes another exam today and he gets a 30, so the arithmetical average of his grades becomes 26. How many exams did he take, ...
1answer
81 views

### Lady Luck Powers Up Every Member to Sum Upto Non-Prime Number. Who am I?

$Given:$ UV, WX, UVCUVWX, are concatenated Numbers. U, V, C, W, X are distinct digits ( zero to nine ). $Relationship:$ $UVCUVWX$ = $U^7 + V^7 + C^7 + U^7 + V^7 + W^7 + X^7$ $Clues:$ 1) UV ...
1answer
152 views

### These Two Cubes are The Only Ones That Are All Pure Prime..name them

Given: CU and BBUE are concatenated Cubes with all prime digits B, C, U, E. Which are these two Unique Cubes?
2answers
237 views

### SAD!!!…System Access Denied..you got three minutes to input three digit passcode

Given Hexagon is super secret system with varying levels of access. Users do not have to remember any password. They just have to answer the questions posed by Hexagon strictly in the allotted time. ...
3answers
444 views

### Palindromic Pan digital Special Square wants you to reveal its Root

All you need is just Mathematical Logic and few minutes. No calculators... no computers. Concise Logic based answers are the preferred choice. Given: Palindromic Pan digital Perfect Square ...
3answers
222 views

### Find this Unique UVC Palindrome ( ignoring signs and decimal) from Given Fractional Relationship

Given: U, V, C are three distinct digits ( 0 to 9 ). UVVVV and CVVVV.U are concatenated numbers. Dot “.” Stands for decimal. Relation: $UVVVV/C= CVVVV.U$ Find U, V , C
2answers
233 views

### Simple Maths Riddle 6

A sixth riddle! There's a function just (reserved) for me though you need three of me to complete it. Don't simplify (me) when the top's much larger; I'll ...
2answers
86 views

### Uvc with Lots of Magic… Enjoy the Show!

Puzzling Weekend! UVc is back again with Lots of Magic... Enjoy the Show! Given: LOTS is being multiplied by F to yield MAGIC. Digit 0 to 9 are all represented by ten different letters in this ...
1answer
288 views

### Simple Arithmetic Puzzle 7. Or is it?

The Arithmetic Puzzles are finally back! The break I took was longer than expected... Let's start easy then. \begin{align}6\times8&=72\\10\times9&=6\\1\times1&=1\\18\times69&=\,?\...
2answers
108 views

### Number of Days in a Year with Consecutive Perfect Squares

Given: Number of Days in a normal Year To Do: Express it in two different ways utilizing Squares of consecutive positive numbers.
2answers
134 views

### Find the values of U, V, C based on the given relationship…useful for upcoming puzzles

Given: U, V, C are 3 distinct digits..values can vary from 1 to 9. CU is a concatenated number Solve for U,V, C from the following relationship: $U^V$ X $V^U$ = $CU$ This will give some basis ...
6answers
338 views

### Pulling Apart a Jigsaw Puzzle

Assume you have a jigsaw puzzle that is also a tessellation. This means every piece has an identical shape and can be assembled into a 2D pattern that fills the plane with no gaps. Such a jigsaw ...
2answers
152 views

1answer
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1answer
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### Join the Fun at Jack’s Casino to get a shot at Jackpot

Jack’s casino dealers are not all prime. But, he gives better odds to get the daily Jackpot by revealing lot more numbers in the sequence in play. That way his Casino is much better than Cryptic ...
1answer
377 views

### It is as easy as A B C, Figure out U V C from the given relationship

Given $U, V, C$ are three distinct digits, figure them out from the following relation: $$\overline{CCC} = \overline{UVUVUV} \div \left ( \overline{UV} \times \overline{UV} \right)$$
1answer
107 views

### Find the missing parking space number [duplicate]

Each space in this parking area is numbered. The parked car covers one of the numbers. What is the number? For reference, the parking numbers are $16,06,68,88,X,98$ where $X$ is the hidden number.
3answers
2k views

### Should I take the antidote? [closed]

A new disease has been discovered in the world, it is called Blue. Statistically 1:1000 people in the world has it and it makes your whole skin blue in a few weeks after getting the disease but not ...
5answers
2k views

### Find the unknown area, x

The image below shows one large rectangle, with smaller rectangles inside it. Your task is simply to calculate the area of the red rectangle, marked with an x. Note that I have deliberately made the ...
1answer
117 views

### Find the first three terms of the sequence

Find the missing values in the sequence: $X, X, X, 59, 2, 65, 3, 58, 9, 79, 3, 23$ Hint 1: Hint 2:
3answers
139 views

### Find the next three terms in the sequence

This sequence consists of triplets; each triplet is linked to each other. $1,36,8,2,48,4,3,60,0,\text{X},\text{X},\text{X}$ The three $\text{X}$'s signify the missing numbers.
1answer
138 views

### Find the immediate square dancing neighbors, they dance together to perfect square

We live in a community of houses sequentially numbered from 1 to 100. We all love square dancing but only two immediate neighbors are joy to watch. If you concatenate their house numbers, it forms a ...
2answers
2k views

### We are two immediate neighbors who forged our own powers to form concatenated relationship. Who are we?

Our concatenated number is $\overline{ABAC},$ where $A, B, C$ are all positive digits (1 - 9). Our relationship is $$\overline{ABAC} = A^A + B^B + A^A + C^C$$ Who are we?
1answer
608 views

### Narcissistic cube asks who are we?

I am a five digit narcissistic cube who likes to display my root right upfront. I also have hidden it in the back of my four digit cube brother. Who are we?
5answers
1k views

### Long digital sequence. 16xxxxxxxxxxxxx61

Find the digital key and very simple method to unlock the long digital sequence 16xxxxxx61 Additional clues: Eeryday one clue will be given till problem is solved Day 1: Bounty Day 2: My code is ...
1answer
106 views

### Number of days in a normal year expressed with five consecutive positive integers [closed]

Given $D$ is the total number of days in a normal year $a$, $b$ are positive integers $P$, $Q$, $R$, $S$, $T$ are consecutive integers Figure them out by combining the following six expressions ...
6answers
2k views

### My Sixteen Friendly Students

I have sixteen students in my class who sit in four rows of four. Each week they sit in a different order. After a number of weeks every student has sat next to every other student, next meaning ...
3answers
2k views

### 99 coins into the sacks

You have 99 coins that you need to place into any number of sacks. After doing so, you write on each one the number of sacks that are lighter than that sack. For example, if you put 98 coins into one ...
2answers
158 views

### Excellent Bike Riders. All under 100. Find the missing members marked x

Excellent Bike Riders. All under 100. Find the missing members marked x. They are all members of special club. 97 X 59 29 X 23 X 7 X
1answer
189 views

### Can you find this abundant dad and his six prime sons?

We are six little prime brothers. All our ages add up to the age of our abundant and old dad who is obviously not in his prime. However, if you pair him up with either of the prime neighbors, they ...
3answers
475 views

### Solve for the Number in the number..square..cube relationship

Each letter stands for a distinct digit...no computer or calculator needed. Just pure logic and some mental multiplication. CUBE is a concatenated number and it is a cube. X denotes multiplication. (...
1answer
130 views

### Surviving the Zombie Apocalypse

It is the zombie apocalypse. Your car has limited fuel in it, and you will not be able to refill your tank once you run out. You are planning one final mission to gather supplies. You have identified ...
1answer
130 views

### He said yes..she said no..they went back and forth..they agreed to [closed]

To call it a Prime. S, N, O are 3 distinct digits that are to be determined by you so that their conclusion is right Full concatenated number: SNOSNOS
2answers
651 views

### Madam I m Adam..please don’t get mad..you will no longer be prime

Take away $\overline{MAD}$ from $\overline{MADMADAM}$ to make her prime. $\overline{ADAM}$ is prime too if he does not get mad: $\overline{MADADAM}.$ $M, A, D$ are 3 distinct digits that ...
1answer
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### XOR: Is it possible to get $a$ and $b$ if I have $a \oplus b$ and $a \times b$?

Intuitively I would say yes but I can't find a way to prove it. I tried with small values and bruteforcing shows that there seems to only be one solution given a distinct tuplet. For example $(1,72)$ ...
2answers
198 views

### SafeCracker #2 - The Mission Continues

Thanks to an alert StackE user, we were able to get the first safe open. Mission Details This next safe is in a former employee's house. He is gone for now, so we have no time to spare. We weren't ...
1answer
89 views

### The NANNP Grid ( Not another Next Number Puzzle )

Simply figure out the last row...
7answers
2k views

### Missing Piece of Pie - Can you find it?

A piece is missing! What should it be?