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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.

-2
votes
1answer
143 views

What is next: 2, 3, 5, 13, 89, 233, …? [closed]

Based on what is shown, what is the next number in the sequence?
3
votes
5answers
151 views

3 as a Sum of 3 Pan Digital Expressions [closed]

$Given$: $3$ = { A } + { B } + { C } Where A, B, C represent 3 unique Pan Digital Expressions. Each contains all the digits 1 to 9 occurs only once. Expressions contain only plus, division ...
-9
votes
1answer
155 views

Starting with e and Pi…how do you get to Phi? [closed]

No equations...need one line answer only. No tricks here.. $e$, $\pi$, $\phi$ are regularly used universal constants. Here is the one line answer: If you want, you can do more to improve accuracy ...
19
votes
2answers
2k views

Diet Coke or water?

At PuzzlingCorp, all employees have a break at 10:00am sharp every day, and immediately proceed to get either plain water or a diet coke. The people at PuzzlingCorp are also highly susceptible to ...
1
vote
1answer
69 views

Express 2222 as a sum of 3 powers in 2 Different Pan Digital Expressions

Solve for the digits in this Unique set of Palindrome- Pan Digital Expressions: $2222$ = $(A/B)^C$ + $(D/E)^F$ + $(G/H)^I$ $2222$ = $(A/B)^I$ + $(D/E)^F$ + $(G/H)^C$ Where, A,B,C,D,E,F,G,H,I ...
0
votes
2answers
61 views

Rep Digit Palindrome expressed as a Unique set of Pan Digital Relations

Allowed Operations: Addition, Subtraction, Multiplication, Division, Exponentiation. Right and Left Bracket use permitted. Express $2222$ In $2$ Different ways using all the digits 1 to 9 only ...
1
vote
3answers
111 views

Express the Squares of first 20 Numbers with only numbers found in their Sum of Digits

Allowed Operations ...Addition, Subtraction, Multiplication, Division, Exponentiation, Simple Factorial. Left and Right Brackets allowed. Expression should involve minimum number of total characters: ...
7
votes
6answers
794 views

Restoring order in a deck of playing cards (II)

Michelle has a deck of 52 playing cards in a pile with their backs facing up. She takes the first 2 cards in the pile, turns them over, and places them at the bottom of the pile. She now takes the ...
6
votes
1answer
192 views

Make a formula to get the highest score

In this puzzle you need to obtain the highest score with the following rules 1) choose two digits from 1, 2, 3, 4, 5, 6, 7, 8 and 9. These digits are represented by two letters, let us say $T$ and $M$...
24
votes
2answers
444 views

The mysterious operation $\oplus$

We are given an operation $\oplus$ that is associative and commutative, has $0$ as a neutral element, and we know: $1/10 \oplus 1/6 = 5/29$ $1/6 \oplus 2/3 = 7/10 $ $1/5 \oplus 2/5 = 3/7 $ $1/4 \...
-4
votes
1answer
124 views

Simple Rule Generates this Sequence from Well Known Number Series

First 6 terms generated on applying the simple rule are displayed here. 5, 8, 18, 102, 322, 1830, ?, ?, ? Hint 1: Hint 2: Hint 3:
-5
votes
2answers
113 views

Numberless Sudoku with Just a Letter and Symbol Combination

A Standard 9x9 Sudoku uses the digits 1 to 9. You are only allowed to use a single letter(say T) and a symbol of your choice to represent the digits 1 to 9. Rules should be well defined and the ...
5
votes
2answers
158 views

Standard Sudoku Specialized with just 2 Primes

A standard 9x9 Sudoku uses the digits 1 to 9. You are only allowed two distinct primes to represent 1 to 9. Find out the minimum number of characters (digits + signs) needed to construct a Sudoku ...
13
votes
3answers
2k views

Restoring order in a deck of playing cards (I)

Michelle has a deck of 52 playing cards, stacked in a pile with their backs facing up. She takes the first 2 cards in the pile, turns them over, and places them at the bottom of the pile. She now ...
5
votes
4answers
849 views

Why did this prime-sequence puzzle not work?

While attacking a recent puzzle (whose solution ended up being entirely different from what I was trying), I was inspired to create a number-sequence puzzle with a sequence $(p_n)$ of primes where the ...
3
votes
1answer
213 views

Happy New Year?

Extend this infinite series by five more terms: 17, 3, 5, 7, 11, 17, 2, 3, 5, 11, 13, 17, 2, 5, 7, 11, 13, 2
9
votes
3answers
573 views

A Mathematical Discussion: Fill in the Blank

I originally saw this on r/puzzles, and thought it deserved a place here. I have a solution to this puzzle, but it's really long and ugly. If anyone comes up with something simple, please share! ...
7
votes
2answers
165 views

A Guide to the Number Rotation Puzzle

This is an extension of What is the strategy to solve Simon Tatham's Twiddle? in that it explicitly goes beyond the default gamemodes of Twiddle The Number Rotation Puzzle (NRP) is a combination ...
12
votes
1answer
375 views

Infinite Sequence based on Simple Rule

Using one simple rule, an Infinite Sequence has been developed. First 30 terms are given. Can you continue the sequence for at least next Ten Terms? Series continues from top left to bottom right. $...
0
votes
1answer
72 views

We are Unique Friends. Our Special Squares Share a Common Bond…Figure us out

Use logical deduction only and document your steps in detail. $Given$: A, B, C, D, E, F, M , T are distinct digits(0 to 9). ABC, EBF, DDABC, MCMABC, TBBB are all concatenated Numbers. $...
32
votes
4answers
6k views

Why is this Simple Puzzle impossible to solve?

Connect each red circle with each black circle by drawing a line and the lines should not touch. From each red circle, 3 lines must be drawn which connect red circles with black circles, but the lines ...
0
votes
1answer
109 views

UVC wants to give you a Helping Hand in Solving these Unique Set of Pan digital Fractional-Decimal Relations

Use pure logic and deductive reasoning only. Document detailed steps in arriving at final solution. You can use calculator minimally. $ Given$: Utilizing These two unique set of Pan digital ...
3
votes
2answers
123 views

Devil in Different Disguises but in Prime Shape…Can you Figure out his Diverse Expressions?

$Given$ $Devil$ goes by $666$ Express him as 1). Sum of all Primes in 3 Different ways using all the digits 0 to 9. Use only + sign. 2). Sum of all Squares of Primes. Use only + and ^ signs. 3)...
12
votes
4answers
846 views

Find the three digit Prime number P from the given unusual relationships

$Given:$ P is a 3 digit prime number Q,R,S,T are distinct digits( 0 to 9 ) QRS is a concatenated number $Relationships:$ $P$ = $QRS + T$ = Reverse of $( QRS * T)$ Find P using just ...
-1
votes
3answers
308 views

WAS IT A CAT I SAW? Do Some Detective Work & Catch The Imposters

Carolina County Community Cat Conference is going on at a resort exclusively reserved for Prime Members. Some look-alike impostors, aka cats, have sneaked in. They all wear fancy name tags that ...
-1
votes
2answers
120 views

Famous Number Displays Dual Cubic Relationships..Figure it out

$Given$: A, B, C, D are all distinct digits. ABCD is a concatenated number $ABCD$ = $A^3$ + $(A+C+D)^3 $ = $D^3+ (A + D)^3$ Figure out this Number and why is it Famous? Also provide ...
6
votes
5answers
317 views

How to Modernize Student Council

You are the math teacher at a high school and you are in charge of organizing Student Council for the whole school next year. Your boss, the Principal, read a research paper on Student Councils and ...
6
votes
1answer
344 views

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 ...
-1
votes
2answers
148 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 ...
1
vote
2answers
90 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, ...
1
vote
1answer
76 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 ...
8
votes
1answer
150 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?
5
votes
2answers
230 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. ...
1
vote
3answers
443 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 ...
5
votes
3answers
217 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
4
votes
2answers
221 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 ...
0
votes
2answers
82 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 ...
7
votes
1answer
282 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&=\,?\...
0
votes
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.
3
votes
2answers
129 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 ...
13
votes
6answers
318 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 ...
2
votes
0answers
243 views

Can you Crack Cohen Family’s Cryptic Codes?

Cohen family of four ...each have their own single numeric code to generate first level access to the system. Before first level access is granted, system displays any one of the 4 single digit codes. ...
3
votes
2answers
150 views

Can you express this orderly Palindromic Devil in strict ascending Pandigital form?

Given: Devil as you know is $ 666 $ Using digits 1 to 9 in strict ascending order and only three mathematical signs ( +, -, /, x ... of these are allowed), write the Pandigital expression $ 666 = ...
2
votes
1answer
99 views

Puzzling Palindromic Year with Pleasing Palindromic Expression.. Please find them

No computers, calculators or searches. Given: The number is a Palindromic year. $PQ$ is a concatenated number. $ U , V $ are two distinct positive integers Expressed as $ PQ ^ U + PQ ^ V + ...
1
vote
1answer
164 views

Be a Wizard..Find the missing digits of this 41 digit Humongous Palindromic Square!

Absolutely No calculators or computers. Only Simplest Method for finding the missing digits will be accepted as the right answer. Given: The square of this 21 digit number $ 229 359 782 235 085 ...
2
votes
2answers
181 views

Cathy’s Composite party is powered by three Prime Pals. Can you find them?

Given: A, B, C are 3 distinct primes. Find the smallest composite number Y that satisfies the relation: $ Y = A ^ C + B ^ B + C ^ A $
1
vote
1answer
85 views

After seeing my 16xxxx16 sequence puzzle, my Younger sibling wants to get into the act and give a little puzzle of his own

In our Reptand prime family, as you know, everybody has our own signature Cycle length. My younger sibling unit has shorter cyclic period and he wanted to create little puzzle for you. He truncated ...
11
votes
3answers
624 views

Five Powers of Fives Produce Unique Pandigital Number…Solve for X..Tell me Y

Given: Y is a Pan-digital Number (no zero, 1 to 9 only) ending in 3. Pan digital number consists of all 9 digits 1 to 9..each digit occurring only once as is the case here. Last digit is given as 3 ...
2
votes
1answer
85 views

Composite Cat Cannot divide its immediate lower neighbors factorial without leaving a remainder

Find this unique composite cat given the information in this title.
5
votes
2answers
133 views

Prime turns into Perfect Cube, if you reverse its digits and subtract…What is the number

Given: 1) I have more than one digit. 2) Reversed number is subtracted to give at least 2 digit number which should be a cube. 2) you don’t even need a calculator to figure me out. Who am I?