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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3
votes
0answers
128 views

Trying to figure a math puzzle/equation for a surprise trip using the date [on hold]

I planning a surprise trip for my husband's 40th. He is a math geek. I am not. My plan is to tell him in a series of riddles/puzzles that he needs to figure out. We are going to LA to see his ...
6
votes
1answer
149 views

What are the house numbers?

Following the last question " What is the corner house number?" here is possibly a more challenging version. Fill in the missing house numbers on the map shown below. The area is occupied by math and ...
6
votes
1answer
264 views

Very easy trigonometry question

There is a very well-known family of right triangles in Mathematics called "The Imperial triangles". Let me explain you how they are defined: We say $T_n$ is the $n$-th Imperial triangle if these two ...
5
votes
1answer
238 views

map 5 unequal ranges to id

This is actually coming from a business place, but it's all about being able to do math tricks, and that's why I'm posting here. I want to implement the following function: ...
0
votes
0answers
114 views

Lockpicking combinations [closed]

A locksmith uses the tool below to pick a tumbler lock with 6 pins and 6 possible pin heights. Suppose she already knows the correct sequence in which to try the pins. How many combinations will she ...
10
votes
4answers
2k views

A Magic Diamond

Place 15 different positive integers on the vertices of this graph so that the ten products of three numbers in a straight line are all equal.
14
votes
1answer
418 views

What is a NaturaW Word™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles. If a word conforms to a special rule, I call it a NaturaW Word™. Use the ...
0
votes
2answers
152 views

Hunting for treasure in 1-d grid [duplicate]

In a castle, there are N rooms in a line. Each room has a door to the two neighbouring rooms (or the one neighbouring room, for the rooms at either end). A treasure is hidden in one of the rooms. ...
6
votes
2answers
834 views

Big number puzzle

I saw this on rec.puzzles many years ago, but can't find the reference to credit the source. I am thinking of a large number. If you want to multiply it by a two digit number $ab$ with $a \lt b$, ...
15
votes
1answer
874 views

Box of tablets, whole or broken: solution required

This is a puzzle that I thought up whilst taking a course of meds. I currently haven’t solved it, and would be curious to know if anyone has a solution for it. Here goes: Scenario: John has a box of ...
3
votes
1answer
166 views

Missing Number in a Seven Segment Circle

What number should replace the question mark? Please be helpful. If you have the answer, please reply to this post with the explanation and answer. If you don't have the answer, then don't comment. ...
7
votes
2answers
274 views

Alice and Bob play at cards

To pass the time Alice and Bob play a simple game of chance where cards are drawn in pairs from a shuffled standard 52-card deck. If two red cards are drawn Alice wins the round. If two black cards ...
0
votes
1answer
103 views

What value will be replaced by question mark? [closed]

I can't find any answer The options are: (a)18. (B) 16. (C)10. (D)12!
11
votes
1answer
654 views

Ernie and the Superconducting Boxes

I was in anticipation all last week. Ernie, who had been travelling for several months, was finally coming home. So over the weekend I dropped in on him. He was bursting with news. "Some wonderful ...
-2
votes
2answers
166 views

I need a solution for this puzzle [closed]

This is meant to be a simple puzzle Given that: 3 - 4= -1 5 + 3= 7 2 + 6= 15 30 / 6= 20 Find: 20% of the sum for the final answer Hint: Final Answer Format: 00/0=0 (/ = ÷) (Divide Symbol)
2
votes
0answers
176 views

Find the missing element?

I've been trying to solve this for quite some time, can you help me solve it? This puzzle was made by one of my friend's teachers. This is not copyrighted and cannot be found anywhere on the internet. ...
11
votes
2answers
3k views

The grades of the students in a class

You are a new Math 102 professor in a university class of 88 students and would like to learn their grades from previous semester to know your students better and put a note of it to get an idea how ...
-9
votes
1answer
136 views

What number I am? [closed]

I am a 4 digit number The digit in the ones place is 6 The value of the digit in the hundreds places is 500 The digits in the tens and thousands places are the same and they add up to 8 What number I ...
2
votes
1answer
164 views

How to solve the input output puzzle?

Here's the puzzle I am solving daily input-output challenge questions in the gradeup android app in order to take preparation for SBI (State Bank of India) PO (Probationary officer). Here I came ...
10
votes
2answers
419 views

#, %O, and so on

I woke up this morning to find someone had added a new button to my basic calculator. Besides the $+$, $-$, $\times$ and $\div$ buttons, there's now also a $\#$ button. I figured, "Well, this probably ...
3
votes
1answer
176 views

Four coins on my desk

I have four coins, all of which are United States currency, on my desk. Some of these coins are face up, and the rest are face down. I know the following facts about the four coins: 1) Each of the ...
2
votes
0answers
81 views

Complete the series on this set of numbers [closed]

Here is one that I can't seem to solve: Complete the following series: 529, 531, 542, 544, 561, 558
3
votes
2answers
236 views

5 Precommitting Pirates Puzzle

Another variant of the Pirate Puzzle, inspired by this variant and a bit more complex. Scenario: Five pirates of different ages obtain 100 gold pieces in total, and want to decide how to split them. ...
-3
votes
1answer
184 views

we are five we have three thousand four hundred fifty who are we? [closed]

we are five we three thousand four hundred fifty, who are we ?. Its a riddle like question but stranded with getting the answer for this question , am very sure the answer will make me slap my head ...
5
votes
1answer
274 views

5 Negotiating Pirates Puzzle

5 pirates of different ages have a treasure of 100 gold coins. On their ship, they decide to split the coins using this scheme: The oldest pirate proposes how to share the coins, and ALL pirates (...
2
votes
2answers
245 views

Minimize sum of guesses to win lottery

Ten boxes are given with $a_1,a_2,a_3,a_4,a_5 ......a_{10}$ number of balls in them respectively .These boxes are randomly ordered but $a_1,a_2 .....a_{10}$ is told.We can arbitrary select a box and ...
4
votes
1answer
111 views

The ultimate conversion of a square into right angle pyramid

This is a follow up of other puzzles. Here a general case of which the other cases are a subset. Given a square of any size, cut it into four pieces to be reassembled into a right angle pyramid (the ...
2
votes
0answers
115 views

What should be the missing number? [closed]

What would be the missing number?
2
votes
1answer
127 views

Oops! Mixed up Multiplication - Needs to be Fixed

$Given$: $U$, $V$, $C$ are distinct digits, varying from 1 to 9. $U$ > $V$ > $C$ $UVC$, $VCU$, $CUV$ are concatenated Numbers $(UVC)*(VCU)*(CUV)$ = $234235286$ The digits on the right hand side ...
11
votes
6answers
2k views

Some interesting calculation puzzle that I made

So I'm creating some kind math puzzle that goes like this: 1=-2+3 12=3*4 123=(4*5)+(6+7)*8-9+10 (thanks JS1 for finding shorter one) 1234=(5*6*7*8)-(9+10+11+12+13+14+15+16+(17*18)+19+20+(-21+22)) ...
1
vote
2answers
154 views

Is it possible to reach 00?

Ann and Bob are going to play a game. Ann chooses a two digit numbers from 01-99. Bob then mirrows the number and adds the checksum to this number and announces the result to Ann. The players then ...
8
votes
2answers
740 views

IX-NAY on the IX-SAY

Will this sequence ever have a 6 in it? 9, 1, 1, 1, 10, 3, 1, 1, 10, 5, 1, 1, 10, 1, 5, 2, 1, 1, 10, 1, 1, 1, 5, 4, 1, 1, 10, 3, 1, 1, 5, 1, 1, 1, 5, 2, 1, 1, 10, 5, 1, 1, 5, 3, 1, 1, 5, 4, 1, ... ...
2
votes
1answer
116 views

What is the Last Digit in the Result of the given Expression? [closed]

$Given$: $ASC$ is a concatenated number with distinct digits. $S$ is square of $A$, $C$ is cube of $A$ Deduce the last digit of the following Expression through Deductive Reasoning only: $$\begin{...
2
votes
1answer
351 views

What's the missing number?

$\begin{array}{ccc}6&7&4\\ 4&11&14\\ 13&2&11\\ 6&8&1\\ 15&3&?\end{array}$ Own attempt at building a puzzle, find the missing number.
1
vote
1answer
52 views

Pan Digital Split among Two Powers

$Given$: $AB$, $DBCE$,$AGFPQR$ are three concatenated numbers with all distinct digits varying from zero to nine. $AB^C$ = $DBCE$ $AB^F$ = $AGFPQR$ Deduce all the digits through logical reasoning ...
-5
votes
4answers
157 views

Go for the Gold

You are given a bag containing 1 and 2 ounce gold rounds. You need to draw one coin at a time till they Sum up to ten rounds. How many different ways you can achieve that? What is the quickest path ...
1
vote
1answer
87 views

Express the given Fractions as Continued Fractions

Using only the numbers, $1$, $2$, $12$. No concatenations allowed. Only permitted signs are plus and division. Brackets are not needed. Expressions should be as concise as possible. Typical ...
3
votes
1answer
185 views

Holy Alphabet Arithmetic

$Given$: $A$+$B$+$C$=3 $B$+$C$+$D$=3 $C$+$D$+$E$=1 $D$+$E$+$F$=1 What is $E$+$F$+$G$=?
-5
votes
1answer
102 views

Fibonacci again..Distinct Digits..Detail all your Deductive Steps [closed]

$ABB$ $CDE$ $GFB$ $DPGB$ $QPFR$ $RDFD$
1
vote
1answer
72 views

Figure out this Four digit Palindrome with two distinct digits and

The sum of the digits of the palindrome is Same as the number remaining after last two digits are removed.
2
votes
1answer
117 views

Deduce Distinct Digits of the Given Fibonacci Sequence- Detail all Steps

$DEPUS$ $SRST$ $UDQD$ $CTQU$ $DTPR$ $PQR$ $SDE$ $VRR$ $CVV$ $DUU$ $QP$ $TT$
3
votes
1answer
165 views

Valiant Knight is back..but he is in grave danger from the Evil Queen

King has placed a bounty on Valiant Knight and enlisted his evil queen’s help. Queen knows knight’s regular stops of his journey and knows he goes through all odd prime cells. She strategically ...
-3
votes
1answer
79 views

Strange? Primes and Palindromes have no business being in this Place?

$1$ $1$,$2$ Good easy start $1$,$2$,$4$ As expected $1$,$2$,$4$,$8$ I know it is going to be easy $1$,$2$,$4$,$8$,$16$ why is he giving this? I got it! $1$,$2$,$4$,$8$,$16$,Prime ...oops!.....
0
votes
1answer
76 views

How do you make Prime “COMPUTERS”?

$Given$: $COMPUTERS$ is the smallest Pan Digital containing all the digits 1 to 9 occurring only once. $COMPUTERSV$ is a Prime only when one of the correct digit ($V$)is added at the end. Also, $...
4
votes
1answer
82 views

What is my number in circle? [duplicate]

N > 1 people sit in a circle clearly seeing all others. They are going to be blindfolded and, while in this state, hats are put on their heads - one per person, naturally. On each hat there is written ...
7
votes
2answers
240 views

Listen to my Story…Let us find the Unique Invisible Pan Digital Pair

I was an avid reader of Popular Science magazine. In the last page or so, they usually had visual clues without words to make useful stuff. I always wanted to create a mathematical puzzle like that ...
12
votes
5answers
750 views

Cup and Trade: The Perfect Nutmeg Soup

Your package from Orinoco has finally arrived! It's the Master Chef's Environmentally-Friendly Measuring Cup Set. It comes with 64 measuring cups having a volume of 1 cup, 1/2 cup, 1/3 cup, 1/4 cup, ....
2
votes
1answer
101 views

All Aboard..Hop onto the Power Train to reach Destination Unity

Your goal is to reach the destination unity. starting from $3462$ with three intermediate stops. You are allowed to use only 2 mathematical operations..multiplication and Exponentiation. All the ...
9
votes
4answers
534 views

The Football Squad

The sixteen players of a football squad, wearing shirts numbered 1 to 16, have arrived in town for a tournament. At their hotel, they are assigned 16 rooms consecutively numbered. Moreover, each of ...
21
votes
8answers
3k views

Robots in a spaceship

Xerxes has 6, 7 and 8-arm robots in his spaceship. Unfortunately, the 7-arm robots are misprogrammed and everything they say is a lie. The other robots are fine, they always speak the truth. Once ...