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2 votes
2 answers
179 views

Quirky chasing problem along train network [closed]

Echidna and Numbat are friends, so they decide to go on vacation together to visit Central American caves and volcanos. But these two friends have very different traveling philosophies. Numbat prefers ...
Astrid's user avatar
  • 21
7 votes
1 answer
836 views

More Catching of Cats

After my first puzzle on this theme was solved relatively quickly, here is a (trickier) follow up question in the same vein! The setup is similar - you are in a room with an infinite line of boxes, ...
Tim Seifert's user avatar
  • 2,477
19 votes
4 answers
2k views

Catching a Cat on an infinite Line

Upon entering a (very) large room, you are faced with an infinite line of cardboard boxes that are labeled, in order, by the nonnegative integers. In one of these boxes, a cat is hiding, but you do ...
Tim Seifert's user avatar
  • 2,477
7 votes
4 answers
403 views

How will the wolf catch the sheep in minimum time?

A wolf is trying to catch two sheep. At time $0$ the wolf's at $(0,0)$ and the sheep are at $(1,0)$. All animals move continuously in real time and react instantaneously according to each other's ...
Eric's user avatar
  • 6,536
17 votes
6 answers
1k views

Can you stop copy Alice?

At time 0, Alice and you both move freely at speed 1 on the plane. As each hour passes, all copies of Alice will subdivide into 2, each moving at half the speed of the parent. So if left alone, at ...
Eric's user avatar
  • 6,536
4 votes
1 answer
181 views

Can you Avoid the Spear-Wielding Gladiator?

You are trapped in a circular coliseum, and a gladiator with a spear is chasing you. You can't defend yourself, but you can run faster than the gladiator. You run at 11 feet per second, and the ...
jjj's user avatar
  • 41
1 vote
1 answer
323 views

Can you escape from two lions?

You're at the center of a circular arena. A pair of lions are at the border, planning to catch you. One of them moves as fast as you, but the other moves slower than you. The three of you are confined ...
Eric's user avatar
  • 6,536
16 votes
2 answers
891 views

Can the lion protect the sheep from the wolves?

In a closed arena, three wolves are on the vertices of an equilateral triangle at the border. The sheep and his lion friend are at the center. The wolf eats the sheep if their distance is $0$, and ...
Eric's user avatar
  • 6,536
25 votes
12 answers
4k views

Can the cop catch the thief?

The cop and the thief, both mathematical points, live in an open interval $(0,1)\subset \mathbb{R}$. That is, their universe is a line segment of length 1 without the 2 endpoints. We know that both ...
Eric's user avatar
  • 6,536
0 votes
1 answer
150 views

Catching the Vegetable-Goose [closed]

After an altercation involving giant bees, you have been sentence to some hard labour, specifically harvesting barnacle-lambs: a gourd-like fruit that grows geese in its shell While working, you get ...
Ichthys King's user avatar
  • 1,487
19 votes
4 answers
1k views

How long can you survive at the devil's playground?

The devil has trapped you in his playground. The devil knows that you can't cross over the burning boundary of his circle, so he allows you to choose a position within the circle before he starts to ...
Eric's user avatar
  • 6,536
2 votes
1 answer
417 views

1 lion, with a zebra and a fixed enclosure

Background See the puzzle Variant of lion and 100 zebras from @ghosts-in-the-code which remains unsolved years after it was posted. Several times in the last couple of years I've started to write up ...
Steve's user avatar
  • 3,885
13 votes
3 answers
1k views

Can the policeman actually catch the thief, instead of shooting?

The ACLU won a lawsuit against the Squareshire Police Department, alleging that his policy of shooting suspected thieves on sight was unconstitutionally excessive force. The argument that carried the ...
hmakholm left over Monica's user avatar
74 votes
5 answers
8k views

Can the Policeman catch the Thief?

The town of Squareshire has six streets: four sides of a square and the lines joining the midpoints of opposite sides. $\hskip2in$ A policeman is chasing a thief along these streets. If they are ...
Ankoganit's user avatar
  • 19.7k
10 votes
2 answers
822 views

Sly Cooper and the Space Police

Last Space Police question... Sly Cooper has landed on a deserted planet with 2 policemen. He is moving around the planet, painting a line along his path, claiming any land which is surrounded by ...
Puzzle Prime's user avatar
  • 6,964

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