Tagged Questions
1
vote
2answers
37 views
Logic puzzle to prove which relative is male or female?
C, D, E, F, G, H, and I are the father, mother, aunt, brother, sister, wife and daughter of J, but you do not know which is which. But you know that:
E and F are the same gender.
C and D are of ...
2
votes
1answer
161 views
Another hat problem
A finite number of prisoners, after being given their hats (black or white), are able to see one another but themselves, and then they are ordered to jot down their guess on the color of their own ...
2
votes
1answer
72 views
Riddle - cover a $62 \times 66$ board using only $341$ straight rows of $12$ squares each
Is it possible to cover a $62 \times 66$ board using only $341$ straight rows of $12$ squares each?
1
vote
2answers
106 views
Interesting and irritating problem.
How to deal this problem. I found this problem in math competation in 2012. But, I could not solve. Could you help me...
Uncle John has taken blood pressure drops for a long time according to the ...
1
vote
1answer
180 views
Spivak Chapter 2, problems 27 (and 28)
To be honest, I have no idea how to even start this problem. I'm sorry I don't have any work to show, but I'm just at a blank. Help?
Chapter 2: Problem 27:
"University B, once boasted 17 tenured ...
-4
votes
4answers
6k views
Puzzle of number grouping
Combine the three numbers in each group to get the same result in each of the three groups. You can use addition, subtraction, multiplication, division, and exponentiation. Here's an example of a ...
4
votes
3answers
137 views
What is the value of D here?
Number S is obtained by squaring the sum of digits of a two digit number D. If the difference between S and D is 27, then the two digit number D is?
My thoughts:
Let the two digit number $D$ be ...
0
votes
4answers
288 views
Can you help me solve these questions related to a Logical theory?
In a group of 200 people, number of people having at least primary education (assuming - Category I): number of people having at least middle school education (Category II): number of people having ...
1
vote
1answer
134 views
In how many ways ( using only whole numbers ) can we divide 49 into 6 parts so that we can obtain any number between 1 to 49?
The series which forms the basis of all the other series is:- 1,2,4,8,16,18.
Some other combinations are:- 1,2,3,7,14,22 ; 1,2,4,7,15,20 ; 1,2,4,8,13,21. However, I obtained the basic combination by ...
6
votes
4answers
231 views
A math teacher thought of a positive integer of two digits.
A math teacher thought of a positive integer of two
digits. She wants her two intelligent students Hanna
and Charlie determine the exact number thought.
For this, Hanna is privately told how many ...
2
votes
1answer
127 views
Four men seated in a boat puzzle
I am looking for an elegant way to solve this rather simple logic puzzle using mathematical logic (statements, conjunctions, disjunctions, implications, tautologies, predicate logic and so on). I am ...
0
votes
1answer
45 views
homework cheyenne
It is a four-digit number.
Its largest place value is its one place.
The squares of each of its digits are less than nine.
Its thousandths didgit divided by its ones digits is 50%.
The sum of two pf ...
1
vote
2answers
163 views
A coin-weighing puzzle with 80 coins
In 80 coins one coin is counterfeit. What is minimum number of weighings to find out counterfeit coin?
PS: The counterfeit coin can be heavy or lighter.
2
votes
2answers
123 views
Number of songs sung.
There were 750 people when the first song was sung. After each song, 50 people are leaving the hall. How many songs are sung to make them zero?
The answer is 16, I am unable to understand it. I am ...
3
votes
1answer
94 views
Square covered with tiles
A square $666\times666$ has been covered using tiles $5\times1$. A single square $1\times 1$ hasn't been covered.
Find in how many places the not covered square can be.
2
votes
1answer
203 views
Sliding puzzle disjoint sets proof
Prove that the states of the 8-puzzle are divided into two disjoint sets such that any
state in one of the sets is reachable from any other state in that set, but not from any state in the other ...
0
votes
2answers
142 views
Logic puzzle about travel times and distances
Each of the four person – Pawan, Rahul , SGR, Ankit –travelled at a different uniform speed out of 10 km/hr, 15 km/hr,20km/hr, and 25 km/hr for different time durations- 30 hours, 40 hours, 50 hours ...
0
votes
1answer
131 views
Diagramatic Puzzle
This is the Puzzle:
and this is the hint:
and the answer seems to be 000111 but I have absolutely no idea how it is done. Can anyonw help me out here?
That's the puzzle. There are no other ...
0
votes
1answer
121 views
how many of relatives are female
I am working on this problem but I am not so sure my answer is right. The question is below with multiples choices but there is only is right.
...
2
votes
3answers
311 views
A tricky math problem about the difference of 2 squares
Jose is given two 2-digit numbers AB and CD where (A, B, C,
and D represent unique digits) and is told to find the
difference between the squares of these numbers.
However, Jose has dyslexia and ...
4
votes
1answer
2k views
Puzzle - 123456789 = 100 with three operations?
Given the sequence 123456789:
You can insert three operations ($+$,$-$,$\times$,$/$) into this sequence to make the equation = 100.
My question is: is there a way to solve this without brute force? ...
2
votes
4answers
356 views
Show that every prime $p>3$ is either of the form $6n+1$ or of the form $6n+5$
Show that every prime $p>3$ is either of the form $6n+1$ or of the form $6n+5$, where $n=0,1,2, \dots$
1
vote
1answer
269 views
The Game of Nim
A position in Nim consists of some piles of coins. Two players alternate, with each move removing a portion of one pile. The winner is the player who takes the last coin.
Suppose that the starting ...
2
votes
3answers
447 views
What is the highest number that can be got from 4383 by moving exactly 2 matches?
What is the highest number that can be got from 4383 by moving exactly 2 matches?
Number 1 has got 2 matches, so I thought it will be 47831 as I remove two matches from second number (3), but it ...
3
votes
3answers
296 views
grid puzzle about combinatorics
Here is a puzzle about combinatorics.
Suppose you have a square grid with $n^2$ points. You want to go from the origin $(0, 0)$ to $(n-1, n-1)$. Assuming you can only go right or up, in how many ways ...
2
votes
1answer
151 views
How do you convert this diagram into a linear system of equations/matrix form?
Question: Given is the following pipe system:
the pressure in a stationary state is at every end and cross-point (with exception of $K_i, i ={1,...,4}$) equal to the average pressure of the ...
3
votes
1answer
373 views
Matrix and Binomial Coefficients
Considering the construction of a matrix as follows.
The $n$th row in the matrix is filled with the coeffcients of $x^r$ in the expansion of $(1+x)^n$ from the columns $2n$ to $3n$ inclusive and ...
