Recently Active Questions
29,037 questions
1
vote
1
answer
119
views
3
votes
1
answer
114
views
Raven's matrix: circles with loops inside or outside
Link: https://sep.stanford.edu/sep/jon/raven/
This is the last question on a Raven's Matrices style IQ puzzle. Question 60 of 60. What is the answer to this puzzle? My guess would be option 2... ...
- 2,192
14
votes
7
answers
930
views
A phenomenal riddle
I’m a natural wonder, hitched to a star.
You could say I’m like an electric car.
I’m hard to see, and some think I’m rare.
I’m so fast, you may wonder if I’m there.
You can try to find me where the ...
- 1
2
votes
2
answers
147
views
A riddle for your time (8)
I mark your thoughts but leave no trace,
I’m silent, swift, and keep your pace.
I vanish fast when you forget,
Yet shape the future’s alphabet.
What am I?
- 301
10
votes
2
answers
823
views
Can you dissect a 5x9 rectangle into nine (or ten) rectangles and/or squares?
Warmup Question:
Can you dissect a 5x9 rectangle into nine rectangles and/or squares such that all rectangles and/or squares have integer side lengths and none of them have the same dimensions? For ...
- 1,950
5
votes
1
answer
689
views
Fastest checkmate by castling
Given that the two chess players cooperate, what is the fastest checkmate with the castle (either White's or Black's) as a final move?
- 3,486
6
votes
7
answers
502
views
Web Site Log: logic grid
I recently began creating my own logic puzzles. I thought I'd share some, from easy to hard here. Here is an easy one to get you warmed up!
Puzzle Information
A group of friends - John, Heather, and ...
- 10.9k
1
vote
3
answers
56k
views
Use the numbers 8 6 4 2 = 25
Use the numbers 8,6,4,2 and the operators +,-,*,/ to get 25.
You can use each number once.
Each operator can be used once.
The least number of operators you use the better answer will be.
- 27.6k
8
votes
3
answers
637
views
Can you swap the positions of the 8 Chess bishops?
Goal:
Swap the bishops so that at the end the white bishops completely fill the top row and the black bishops completely fill the bottom row.
Details:
Move bishops one at a time according to standard ...
- 18.4k
16
votes
2
answers
3k
views
My Three Children
The sum of the ages of my three children is 40. Though the ages of my two daughters are relatively prime (i. e. they have no common divisor), the age of each of them does have a common divisor greater ...
- 10.9k
2
votes
1
answer
271
views
Word Search - Find the hidden words
There are 2 hidden words here, except the given words below:
Words
ACETIC
ACTOR
CRUDE
ERODE
ERUPT
KNOWLEDGE
PEANUT
PITCHY
QUEEN
RACIAL
URBAN
And here’s the code for second hidden word:
...
- 2,712
13
votes
2
answers
361
views
The Flow of Time
Something is haunting me.
Aaaeellmnn Otuvyz
aeh Llnor
dghiin Nsstu
aaeeg Lmrtvv
beei Lnot
eeh Innor
What am I haunted by?
- 310
3
votes
1
answer
382
views
How many chess pieces does it take to "cover" all spaces on a chessboard if you must have at least one of each type?
Given an 8x8 chessboard, your goal is to "cover" each space on the board with the fewest possible number of pieces. The extra restriction is that you must have at least one of each type of ...
- 16.8k
22
votes
10
answers
4k
views
Flashlight and 8 batteries
Source: this TED-Ed video.
A flashlight requires 2 AA-type batteries to operate. Both these batteries need to be charged for the flashlight to provide light.
We happen to have 8 batteries, but 4 of ...
- 1
37
votes
4
answers
18k
views
How many chess pieces does it take to "cover" all spaces on a chessboard?
Given an 8x8 chessboard, your goal is to "cover" each space on the board with the fewest possible number of pieces. A space is "covered" if there is a piece on it, or if a piece on the board can be ...
- 519