Questions tagged [real]
For puzzles that presented themselves, with real parameters and consequences, during otherwise non-puzzling activities.
25
questions
8
votes
3
answers
817
views
Odd hours with two timers
Two motorized 24-hour
light timers
are daisy
chained
between a power outlet and a light bulb.
For these timers, devise schedules and choose initial times
that produce the following repeated 9-hour ...
- 21.8k
8
votes
3
answers
619
views
Halve time with two timers
Two motorized 24-hour
light timers
are daisy
chained
between a power outlet and a light bulb.
For these timers, devise schedules and choose initial times
that produce the following repeated lighting ...
- 21.8k
21
votes
11
answers
4k
views
What's wrong with this line in a baking recipe book?
A cookie-baking recipe book (this one, specifically) has the following instruction in it, which is incorrect in a single spot:
If you have a fan-assisted oven, you will need to reduce the recipe ...
user88
12
votes
3
answers
1k
views
9
votes
2
answers
502
views
Third timer's a charm
Three motorized 24-hour
light timers
are arranged between a power outlet and a light bulb,
with timer A parallel to a daisy
chain
of timers B and C.
For these timers, devise schedules
that ...
- 21.8k
16
votes
4
answers
4k
views
Is there a secret message in the first decimals of PI?
Is there a secret message encoded in the first decimals of $\pi$?
Source: Vi Hart
- 76k
5
votes
8
answers
819
views
A strange sight in London
While travelling in London, I noticed something strange.
I saw some numbers which appeared to be counting up but which then switched to counting down. Later on, I saw the same thing, but the numbers ...
- 1,084
81
votes
2
answers
4k
views
A good puzzle is a double-edged sword
A rare double-edged sword is currently on loan from the British Museum to the Magna Carta exhibition.
The sword itself is described as likely made in Germany around 1250-1330 and includes the ...
- 5,280
75
votes
8
answers
24k
views
My friend sent me a photo of his keyboard, but there's something I can't figure out about it
Two months ago, my friend bought a new Chromebook. He told me yesterday that while he is happy with the computer overall, he's not that impressed by the quality of the keyboard. My friend is an ...
- 1,927
54
votes
1
answer
6k
views
Unsolved Mysteries: D'Agapeyeff cipher
The D'Agapeyeff cipher is an as-yet unbroken cipher that appears in the first edition of "Codes and Ciphers", an elementary book on cryptography published by the cryptographer Alexander D'Agapeyeff in ...
- 681
36
votes
3
answers
4k
views
Unsolved Mysteries: Magic Square of Squares
This is the first in what will hopefully be a series of Unsolved Mysteries posts.
Note that this puzzle has no known solution, nor any proof that a solution is impossible. We will see how ...
- 25.7k
35
votes
3
answers
3k
views
Is this more than a packing puzzle?
I bought this set of wooden blocks at a garage sale today, and although it was a challenge to fit them in the box, I suspected they were more than just a packing puzzle. Can you guess what else they ...
- 2,572
32
votes
9
answers
9k
views
Should I Take the Bus or Refill My Bottle First?
This is a real-life puzzle encountered by one of my friends.
I want to arrive early to my class today. Exactly every $7$ minutes, there is a bus that arrives at the station near my dorm and will ...
- 34k
29
votes
2
answers
6k
views
Does this metal puzzle have a solution (Baguenaudier)
When I was young I got this puzzle as a gift to me.
The aim is to get the long piece out. I haven't yet found a solution, and I'm not sure if there is one
Does this have a solution and if so ...
- 393
26
votes
4
answers
4k
views
The "Loop of rope" dilemma
It's a "dilemma" that I encountered in real life problems. I believe that it's not new and is quite easy to explain, but may look puzzling at first glance.
Alice and Bob are playing with a ...
- 7,357
26
votes
4
answers
2k
views
This image contains a "Great Discovery"
The Puzzle:
Source material taken from here
As discussed on Numberphile, here is John Herschel's doodle, sent to his friend Charles Babbage.
John H.
John Herschel was an English polymath, ...
- 403
26
votes
1
answer
2k
views
Real life puzzle: Unknown alphabet or shorthand
User JellicleCat posted this on linguistics stackexhange a few years ago. None of us were able to come up with a satisfying answer but most seemed to agree that it was an idiosyncratic cipher or ...
- 361
22
votes
11
answers
5k
views
Why is the pavement wet?
Saw this the other day. So I took this picture. There was another nearly identical wet patch 2 spaces away.
Why is the pavement wet?
Note: This is a straight forward physics puzzle. This is a ...
- 371
20
votes
5
answers
2k
views
The Greenhouse Problem
While I was playing a certain popular indie farming game, I came across a dilemma. I have a greenhouse that I'd like to fill as efficiently as possible. How many plants can I fit in the greenhouse?
...
- 874
19
votes
6
answers
5k
views
The falling broom handle
As the reaction to my previous physics puzzle was somewhat mixed, I'll try again. I found this in an online physics book.
You hold a broom as shown in the following picture:
The head of the broom is ...
- 50.8k
18
votes
10
answers
2k
views
Two many rainbows?
Wish I’d had a camera at the time
but a cartoon will have to suffice,
representing two actual incomplete rainbows
that stop in midair where they meet,
lit only by a setting sun.
This seemed so ...
- 21.8k
7
votes
2
answers
1k
views
Don't put yourself out, dear
I asked my mother the other day, "What do you want for dinner? I'll get you anything your little heart desires."
My mother, true to form, radiated the stereotypical motherly vibe: "Don't worry about ...
- 25.6k
6
votes
1
answer
379
views
Calculate total score from average score
A class of students have taken $8$ exams.
The average scores of the exams are:
1st: $80.12$
2nd: $74.59$
3rd: $77.83$
4th: $77.34$
5th: $82.07$
6th: $81.25$
7th: $78.90$
8th: $75.44$
What is the total ...
- 7,357
4
votes
1
answer
151
views
Reconstructing sport climbing results
Sport climbing at the 2020 Summer Olympics – Women's combined
Warmup
Sport climbing is a new event (one of four) at the 2020 Summer Olympics in Tokyo, and it just finished. Two events were held, one ...
- 945
2
votes
1
answer
99
views
Can you produce a wolf's template? Part 2
Here is the first question.
You are given a square piece of paper with no marks on it. With this paper, you have to make a wolf's template.
You are given no tools such as a ruler or scissors, and all ...
- 1,699