Recently Active Questions
29,037 questions
-5
votes
0
answers
143
views
Estimating a sum of consecutive prime numbers [closed]
$p_n = 0.069n^2 + 2.229n - 1.85 \ $ can be used to estimate the nth prime number for $ \ 1 \le n \le 25.$
Using some combination of arithmetic, algebra, calculus, by hand, and a calculator, please
...
- 2,482
6
votes
2
answers
430
views
Making sense of a logic puzzle in Blue Prince parlor room
Context: The game Blue Prince regularly gives the player a specific type of logic puzzle. The setup is that there is a blue box, white box, and a black box. Each box has one or more statements written ...
- 6,060
3
votes
0
answers
152
views
Murder mystery puzzle told through seven news articles [closed]
Project52hz is a puzzle series with different types of challenges, all leading up to something bigger. It’s been tough so far, and only one person on Reddit seems to have made real progress.
The first ...
- 10.9k
11
votes
1
answer
929
views
longest path in 10x10 grid
This puzzle is based on a grid that contains values from 0 to 9 and wildcard *.
Find longest non-intersecting path in a matrix starting from top-left cell and ending bottom-right cell.
Build the path ...
- 10.9k
-8
votes
0
answers
99
views
Find the Missing Number in This Intriguing Pattern [closed]
Examine the sequence below:
1, 3, 6, 10, 15, 21, ?
Identify the number that should replace the question mark.
- 1
1
vote
1
answer
217
views
Can you determine the tasty item?
2111121221
It’s a nice way to end a meal! (7)
This puzzle has nothing to do with phone numbers.
- 74k
0
votes
0
answers
271
views
pilgrimage speed reference [closed]
Three pilgrims $\alpha$ $\beta$ $\gamma$ plan their journey to pilgrim site $D$ which happens to be equidistant from the sides of a right-angled ($90^\circ$ in $C$) triangle having $a < b < c$. ...
- 2,192
29
votes
2
answers
1k
views
A puzzling site... But what am I looking for?
After discovering the name of the treasure map’s owner, I came across something entirely different: a puzzling site.
It felt strangely familiar, as if I had seen it countless times before. This time, ...
- 12.7k
3
votes
1
answer
494
views
Seconds in the balance
The yew and reed
My two better halves
Weather the weather
Bend weather if you need
Never withers, never calves
Hint, added subsequently:
2nd Hint/clarification, added subsequently:
- 8,444
5
votes
1
answer
479
views
What do emotions have to do with it?
The answer is a single word. Instructions on how to find it has been given below.
Hint 1
Hint 2
- 13.8k
3
votes
1
answer
237
views
Breakfast, socks, and diseases
This is my very own logical deduction puzzle I've created with the help of my friend.
It might look difficult, however it is very simple to solve once you make sense of the clues. The multiple ...
- 197
12
votes
2
answers
1k
views
Dissect the almost 10x10 square into 4 congruent pieces.
Your task, should you accept it, is to dissect the following shape into 4 congruent pieces.
Rotations and reflections are allowed. You must cut along the grey lines.
You don't need mathematics to ...
- 32.7k
3
votes
4
answers
199
views
A riddle for your time (7)
Born in a box, I’m killed by light,
I only live when day turns night.
I dance on walls without a sound,
But when it’s bright, I’m not around.
What am I?
- 10.9k
10
votes
1
answer
487
views
+50
Satisfying class choice preferences
There are 30 people in a class and each person chooses 5 other people in the class that they want to be in a new class with. The new classes will each be of size 10. Is it ever impossible for ...
- 8,822
-4
votes
3
answers
210
views
1 22 333 4444 55555 666666 7777777 88888888 999999999
You are given the following 8 numbers:
22
333
4444
55555
666666
7777777
88888888
999999999
Answer the three following sub-puzzles, allowed operators are: $+,-,\div,\times$ and parenthesis.
Obtain 1 ...
- 171