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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.

32
votes
5answers
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 ...
3
votes
1answer
135 views

Normal Knight sees the Big Picture during his Countrywide Travels [duplicate]

Normal Knight is savvy, energy saving as he travels through Regular Country... Ride along and Document Details of his Journey As this Knight (only chess move allowed) journeys through , he takes ...
11
votes
3answers
358 views

How many possible starting positions are uniquely solvable for a nonogram puzzle?

This type of puzzle goes by many names: Nonogram, Picross, and Griddlers are all mentioned on the Wikipedia page, Simon Tatham calls it Pattern, I was introduced to it as Descartes Rainbow, ... The ...
1
vote
2answers
110 views

Magical Knight Moves with Effortless Ease in his Magical Kingdom

Magical Knight knows every Square of his Magical Kingdom. In many respects, he is like any other knight...Literary,Prime, Normal(makes same allowed chess moves). He is people Knight . As he traverses ...
12
votes
7answers
420 views

10 coins, 3 of them are fake

Inspired by some great weighing puzzles here (This being one of my favorites), I just made another weighing puzzle - I'm not quite sure how difficult or easy this one is. You are given 10 coins, 7 of ...
5
votes
3answers
2k views

Too early in the morning to have SODA?

Each letter shown represent distinct digit...can vary from zero to nine. $COCA$, $COLA$, $SODA$ are three concatenated numbers. Figure these out from the following relation: $COCA + COLA = SODA$
0
votes
0answers
78 views

Which number replace question mark [duplicate]

Answer my question that which number will replace question mark.
4
votes
0answers
199 views

Explain the relations between the numbers in the following pattern

$$\begin{matrix} 22 & 12 & 0 & 15 & 18\\ 15 & 27 & 26 & 18\\ 13 & 8 & 22\\ 27 & 13\\ 0\\ \end{...
8
votes
1answer
165 views

One to Eleven Sum to Twenty Five

From the picture shown below, deduce the missing numbers (one to eleven)... none of them repeating. Four Numbers surrounding the Five diamonds A, B, C, D, E, as well as the five numbers in the outer ...
2
votes
1answer
63 views

Fibonacci Cycles Back…Figure out the Fibonacci Number FBN

$Given$: $F$, $B$, $N$, $U$, $V$ are all digits that can vary from 0 to 9..but not necessarily distinct. $FBN$, $NBF$, $UV$, $VU$ are all concatenated numbers. From information given below, what is ...
1
vote
0answers
91 views

What is the missing number in set B?

A {6, 2, 2, 2, 16, 2} B {37, 37, 3, 3, 3, ?} The numbers in set A relate to one another through a numerical or abstract pattern. Set B has a similar or a somewhat contrasting pattern .The task in ...
6
votes
2answers
152 views

Take Twelve to Total Twenty Two

Without repeating the numbers 1 to 12, Fill the grid below to total 22 in both directions. $$\def\X{\smash{\rlap{\Space{7pt}{0px}{0px}\llap{\Huge{\times}}}}} \Large\begin{array}{|c|c|c|c|}\hline &...
-2
votes
0answers
76 views

-4 to 3 magic square [on hold]

Write the numbers -4 ,-3 ,-2,-1,0,1,2,3 in correct place value so that each of the square adds up to 0 Please solve this question, because I have tried this this question many times without success. ...
-1
votes
0answers
90 views
4
votes
0answers
93 views

Answered it badly…on purpose?

Teacher: You got a 0. Miles Morales: Is that...failed? Teacher: Listen. If you answer all questions on a multiple choice test randomly, you would get a 25%. This means the only way for you to ...
12
votes
3answers
1k views

Catching a robber on one line

At x = 0, a thief robbed a bank. The thief ran one of two known directions at a constant speed, towards x < 0 or towards x > 0. The cop arrives at the crime scene some unknown time after the ...
3
votes
1answer
84 views

A Lollipop with Roots

$Given$: $S$, $T$, $U$, $V$. are distinct digits which can vary from zero to nine, with $V>U$. $ST$, $STT$ are concatenated Numbers. Deduce S, T, U, V from the following relationship. $$ST=\...
4
votes
1answer
72 views

An Arithmetic loving Ant crawls to one Hundred

This ant can do arithmetic but can crawl only horizontally or vertically, never diagonally. It starts from one of the cells shown in the picture below. It’s path covers thirteen different numbers ...
0
votes
0answers
53 views

Distinct SemiPrimes with Close Factors

I'm in the midst of developing a game for several friends as a friendly competition. It begins with generating the largest distinct semiprime feasible with factors that closely related in length ...
-2
votes
0answers
65 views

SOLV for Narcissistic UVC

This puzzle highlights some cyclic power Relations. Please provide detailed reasoning of derivation of digits from various power relations given below: $Given$: $A$, $C$, $L$, $N$, $O$, $S$, $U$, $...
5
votes
1answer
115 views

Any Volunteers for Card Counting?

You are given 2 matching card decks with Aces, Kings, Queens, Jacks removed. Now each deck has 36 cards. One deck is shuffled and placed on top of the other deck. Starting from the top card, you ...
0
votes
0answers
62 views

Maximize sum of a Bipartition [duplicate]

We have a sequence of numbers say X. The goal is to divide this sequence into 2 parts such that the sum of the Greatest Common Divisor(G.C.D) of both the sub-sequences is maximum. Note : The G.C.D ...
0
votes
0answers
92 views

A series of blocks (total $n + m$) is given to us and 0 is stored initially in each.We are given a number $H$ and we can choose $H$ blocks at a time

Operation - we can choose $H$ blocks at a time and can fill those blocks with digit 1. we can do this Operation as many times we want. if block has already 1 in it and we are going to put 1 again then ...
4
votes
1answer
133 views

Fill.in the two missing terms in this Simple Sequence

What are the two missing numbers in the sequence shown below: $$\def\S{\phantom{XX}} \large\begin{array}{|c|c|c|c|c|c|}\hline \S&\S&\S&\S&\S&\S\\[-10px] 4 & 5 & 6 & 7 &...
2
votes
2answers
70 views

All the Signs point to the Second Prime…Figure out the Missing Digits

$Given$ The six Interrelated Equations A, B, C, D, E, F All equal to 3. Allowed Digits.. 1 to 9. All the missing 9 are distinct...9?s...9 Different Digits Fillin all the digits that satisfy all ...
-4
votes
1answer
99 views

Prime Sequence…a little bit Unusual about the Missing Members

What are the Missing Members in this Prime Series? what is the Significance of this Sequence? $19$, $17$, $13$, $?$, $?$, $3$, $2$
3
votes
2answers
108 views

Pan Digital Lucky Seven wants you to figure out all the digits

$Given$: A, B, C, D, P, Q, R, S, T are distinct digits varying from 1 to 9. AB, CD, PQ, RST are all concatenated Numbers. From the given expression , figure out all the digits to make lucky seven. ...
5
votes
1answer
112 views

All Raised to the Power of U

$Given$: C, I, L, U, V are all distinct digits and can vary from 0 to 9. $LIV$, $UVC$ are concatenated Numbers. $U^U$ + $V^U$ + $C^U$ = $UVC$ $L^U$ + $I^U$ + $V^U$ = $LIV$ Solve for all the ...
1
vote
5answers
329 views

Create Numbers 1 - 100 using 1,9,6,8

Create all numbers 1 - 100 using equations made up of 1,9,6,8. Rules: Use all four digits exactly once Allowed operations: +, -, x, ÷, ! (factorial), exponentiation, square root. Parentheses and ...
6
votes
4answers
234 views

Savage Road Signs (Part 2)

Please read part 1 or this might be confusing Since part 1, you have replaced the stolen stickers and your daughter has forgiven you. The highway ended up being a full 700km long, so you are happy ...
-2
votes
0answers
19 views

Upside down A (for all) [migrated]

I am working on a voltmeter and the tolerance for it is 0.25% upside down A (for all) 1 digit. I am not sure what exactly what this means. I am guessing if my value was 19.95 'for all' could mean I ...
8
votes
1answer
653 views

I am caught when I was about to steal some candies

I am a eight years old boy, I love candies, but my mom does not want me to eat any more candies because I start to have black teeth :( but I still love candies so... Today when I was about to steal ...
22
votes
4answers
2k views

Savage Road Signs

There is a highway that starts in the city of Savage. You must must place distance marker signs on this highway for the outgoing traffic. According to highway code, there must be a distance marker ...
10
votes
4answers
3k views

Use 1 9 6 2 in this order to make 75

I'm looking for a solution to make number $75$ with numbers $1$ $9$ $6$ $2$ in that order and the same rules as in Use 2 0 1 and 8 to make 67. Here a copy of those rules: You must use all 4 digits. ...
5
votes
3answers
189 views

Find the Missing Members of this Powered Sequence

There are 4 missing members in this small series...labeled ???. Hint 1; Hint 2: Complete the series. $191$, $426$, $931$, $???$, $???$, $646$, $971$, $???$, $???$
5
votes
5answers
339 views

Shortest time to meet

Three runners are located at the corners of an equilateral triangle, 100 meter a side. They run to a point inside the triangle and their goal is to do it as fast as possible. If they run at the same ...
-1
votes
1answer
477 views

Products of three primes that bound RSA numbers [closed]

Let $N$ be some number. Let $R$ and $S$ be semiprimes (ie, each is a product of two prime numbers) such that $R \le N \le S$. For quite a few numbers $N$ we can find $R, S$ such that $S-R$ is small;...
-1
votes
0answers
62 views

sum and gcd june19 challenge! [duplicate]

Can anyone please help me out with the https://www.codechef.com/JUNE19B/problems/SUMAGCD question? "Example case 1: For example, the sequence A can be divided into subsequences B=(4,4,6) and C=(7)." ...
3
votes
2answers
435 views

Let M and N be single-digit integers. If the product 2M5 x 13N is divisible by 36, how many ordered pairs (M,N) are possible? [closed]

Let M and N be single-digit integers. If the product 2M5 x 13N is divisible by 36, how many ordered pairs (M,N) are possible? -- source I tried it by reducing 36 into its positive factors (1,2,3,...
11
votes
2answers
513 views

2019 gold coins to share

You and your friend has found in total 2019 gold coins in a treasure hunt. Since your friend found the place to dig up, he deserves a bit more gold than you so you offer a game to share the coins to ...
5
votes
2answers
148 views

Please figure out this Pan digital Prince

Given: P, R, I, N, C, E, T, O, M are all distinct digits varying from 1 to 9. PCRON, PRINCETOM are two concatenated numbers. PCRON is the highest possible number you can have fulfilling the ...
0
votes
0answers
3k views

Finding maximum possible sum of GCD's of an array of n-elements

A sequence of positive integers A1,A2,…,AN. Split this sequence into two non-empty (not necessarily contiguous) subsequences B and C such that GCD(B)+GCD(C) is maximum possible.Find this maximum value....
4
votes
3answers
92 views

Make 2019 Factorial Multiplication a perfect square

N is not a square number and consists of 2019 factorial multiplication as shown below: $N=1!\times 2!\times 3!\cdots 2018!\times2019!$ At least how many factorial needed to be removed from the ...
3
votes
0answers
2k views

Finding Round Integer

An integer is round if it is greater than $0$ and the sum of its digits in decimal representation is a multiple of $10$. Find an optimal procedure to compute the $N-th$ smallest round integer. E.g. ...
1
vote
0answers
1k views

Finding numbers having exactly two distinct digits

We have $10^K$ road signs (numbered 0 through $10^K−1$). For each valid $i$, the sign with number $i$ has the integer $i$ written on one side and $10^K−i−1$ written on the other side. We need to ...
0
votes
1answer
122 views

Don’t let this daunting equation dissuade you to deduce the desired result

Given: A, B, P are distinct digits. AA, AAA, ABB are concatenated numbers. Relations: $$P=A+A+B$$ $$(AA + ABB)^P-(ABB)^P=(AAA - A) ^P+(B+B^B*B)^P+(B^B)^P$$ Don’t be afraid to make reasonable ...
2
votes
1answer
211 views

Mathematical Sequence Based on Prime Numbers

This sequence is based on prime numbers Hint 1: 16, 17, 11, 16, 10, 8, 13, 7, 14, 8, 11, 7, 5, 10, 4, 11, 5, 10, ?, ?, ? What are the final three numbers?
3
votes
1answer
172 views

A Diophantine rational function [closed]

For how many integers $N$ is the rational function $\frac{N^2-2N-15}{N^2-N-12}$ also an integer?
6
votes
2answers
1k views

What's Bob's age again?

I created this problem myself, but I did have inspiration. Today is a special day, I'm moving out of my parent's house. My father comes to me and says "Wow, you're half my age. On the day we moved ...