Unanswered Questions
29 questions with no upvoted or accepted answers
10
votes
1
answer
752
views
Powerful number systems
Imagine I have two positive integers, $a$ and $b$. Can you find the last digit of the sum $a+b$ given only the last digits of $a$ and $b$? More generally, can you find the last $n$ digits of $a+b$ ...
CommunityBot
- 1
10
votes
0
answers
512
views
I'm a number with a special product, so name me when you think you've got it
In the blocks that come before,
their special product tells us more.
To guess my scheme you'll need calculation,
but only little tests of recreation.
Each block contains atoms strong as Thor,
...
- 2,296
9
votes
1
answer
2k
views
Is there another name for this puzzle? (Kyudoku, Nine Find)
Is there another name for this type of puzzle? I can only find two examples of it online:
https://www.brainzilla.com/logic/kyudoku/
http://ninefind.com/
In the game you start with a 6x6 grid filled ...
CommunityBot
- 1
7
votes
0
answers
168
views
Logic and geometry problem 2
My question is whether or not a deadlock can occur in Crisscross. A deadlock is defined as a position, an arrangement of checkers, in which the board has been filled but neither player has won.
...
- 6,959
7
votes
0
answers
295
views
Who wins the game of "Sticky Gomoku" on an infinite board?
This is a Gomoku like game, played by two players with Go pieces (black and white stones) on an infinite (in all four directions) Go board.
Rules
Four in a row: players alternate turns placing a ...
- 6,536
7
votes
1
answer
1k
views
Name and solution of puzzle to rotate all arrows to same direction
In this puzzle, when you click an arrow, all arrows immediately next to it (diagonally included), as well as the arrow you clicked itself rotate 90 degrees. The goal is to get all the of arrows to ...
CommunityBot
- 1
7
votes
0
answers
315
views
Even and primes puzzle?
These are secret numbers that increase regularly. What are the next two numbers?
If you like numbers, it will be fun.
$2^3 \times224299$
$2^2 \times 3^2 \times 19 \times 3557$
$2 \times 5 \times ...
- 6,581
7
votes
0
answers
374
views
Best moves for a 7X7 4 queen board
There is a 7x7 board and 2 players, each having 2 queens. The queens can move just like the queens in chess, but cannot capture each other. At the beginning, the first player places both the queens on ...
- 3,672
6
votes
0
answers
291
views
Trying to find a 2020 puzzle hunt with a puzzle based on Among Us
I am trying to find a puzzle hunt that I believe was held in 2020. It contained a puzzle based on the game Among Us with 26 characters, and you had to decide who were the imposters. The imposters all ...
- 10.3k
6
votes
0
answers
314
views
Looking for a kid's puzzle, cannot remember title
I'm looking for a kids' logical puzzle I saw in a Brazilian puzzle magazine several years ago. A farmer had a square farm with four houses and twelve trees and he wanted to divide it between his four ...
- 35.6k
6
votes
1
answer
505
views
Late 18th/early 19th century numbers grid
I was researching an historical figure on the Isle of Man, Capt George Quayle (b.1751 - d.1835), and in amongst the museum's papers was this numbers grid which was part of his effects. The museum ...
CommunityBot
- 1
4
votes
0
answers
211
views
King 2 men, but don't kill a man
I found mention of this challenge in a Science paper called "Checkers is solved" from 1996, but no example was given.
Beginning at starting position, play moves according to rules of ...
- 12.9k
4
votes
0
answers
350
views
Are infinite loops possible in the game Prodway?
I'd like to know if infinitely repeating sequences of moves (i.e. cycles) are possible in the following game:
Prodway is a game for two players (Black and White) that is
played on an initially empty ...
- 145
4
votes
0
answers
167
views
encode in encode
Today, a cryptic message was received by Area 51:
Bananatexteismarvellous605185682252125223459314283216133301
2
The staff managed to figure out that some 2 digit ...
- 41
4
votes
0
answers
164
views
Wooden puzzle with multiple balls on strings attached to a central hook, from which metal arms connect top and bottom
I bought this puzzle few years ago at a market. I couldn't solve it since. I started to think it was wrongly assembled, therefore can not be solved. Tried to find the solution on the internet/YouTube ...
- 10.3k