Newest Questions
29,037 questions
5
votes
1
answer
278
views
Progressive matrix: 3x3 grids with some cells shaded blue
It is a progressive matrix. You have to figure out what the bottom right panel should be based on the pattern in the other panels.
- 1,735
24
votes
4
answers
2k
views
Dividing a hexagon into 9 equal regions
Can you divide a regular hexagon into 9 regions of equal shape and area?
- 38.7k
5
votes
2
answers
1k
views
Add 1 line to make a valid equation - 18x18=18
Add 1 line to make a valid equation.
No additional conditions are provided, and X is a multiplication symbol.
The line has to be...
straight, not curved.
not used to cancel something.
However, ...
- 2,712
16
votes
1
answer
385
views
Can you colour these chess pieces?
Here is a new little retrograde chess puzzle! In the position below, only kings and pawns remain on the board. Unfortunately, the lighting in the picture was so bad that the black and white pieces ...
- 8,822
6
votes
2
answers
326
views
Who wins this altered race to 15?
The nine numbers from 1 to 9 are face up on a table.
Two players take turns taking one of the numbers. (Both players can always see which numbers have been taken and which numbers remain.)
A player ...
- 1,347
5
votes
1
answer
304
views
Is the product of square roots of consecutive Fibonacci numbers (starting with 2) ever an integer?
Consider the product:
$ \sqrt{2} \times
\sqrt{3} \times
\sqrt{5} \times
\sqrt{8} \times
\cdots \times
\sqrt{F_n} $
where the integers inside the square roots are the Fibonacci numbers ...
- 27.6k
13
votes
1
answer
369
views
I forgot my friend's name! Can you help me?
i was at my friend's house and i forgot her name. but i found these incomplete tax forms
she was filling out on the ground. so i thought you ppl could help me figure out what her
name is cuz it would ...
- 1,735
17
votes
3
answers
901
views
Can you find sets of 4 (or 5) positive integers such that their pairwise sums give consecutive numbers?
Warmup question:
Is it possible to find four positive integers such that their pairwise sums give six consecutive numbers?
Main question:
Is it possible to find five positive integers such that their ...
- 27.6k
6
votes
3
answers
1k
views
Magic fifteen. Who wins the race to 15?
Take nine slips of paper and number them from 1 to 9, then lay them face up on a table.
Two players take turns taking one of the numbers (that is, one of the slips of paper).
The game ends when either ...
- 27.6k
2
votes
5
answers
401
views
Can you get 100 using only 9,1,6,6 each once? [closed]
I was playing Math Flux and the winning goal was 100. We had combined digits out so we can combine 2 digits together
Can you get 100 using the digits 9,1,6,6 using only each digit once?
- 39
9
votes
2
answers
293
views
Replace the variables with something.
Given
$$ 2X5Y9X2 = 2592 $$
replace $X$ and $Y$ with something to make this equation true.
This question is similar to this.
- 1,112
6
votes
1
answer
290
views
4
votes
2
answers
305
views
Rooms and glases [closed]
Riddle:
You have two rooms. In the first room, there are two glasses, one of which contains poison. In the second room, there are four glasses, two of which contain poison. You are required to choose ...
6
votes
2
answers
567
views
Odd neighbors. Can you place coins on a 6x6 chessboard so that every square has an odd number of adjacent squares that contain a coin?
Can you place coins on a 6x6 chessboard, at most one coin per square, so that for each square, whether occupied or not, the number of coins on adjacent squares (sharing a common edge) is odd?
...
- 27.6k
17
votes
0
answers
333
views
Edge Removal Game
There is a complete undirected graph with n nodes (n > 1). Alice and Bob take turns removing one edge from the graph, with Alice going first. The player whose move causes any node to become ...
- 1,182