Puzzling Stack Exchange
Puzzling Stack Exchange

Questions tagged [river-crossing]

For questions regarding how to get items or people across something obeying a set of rules.

For questions regarding how to get items or people across something obeying a set of rules.

The most famous example would be the Fox, Goose and bag of beans, or variants of it, in which a farmer has to get a fox, a goose and a bag of beans across a river.

However if the fox is left alone with the goose it will eat it and if the goose is left alone with the beans it will eat them. Nothing eats anything else when with the farmer.

The solution to this would be

  • Take the goose over
  • Return
  • Take the beans over
  • Return with the goose
  • Take the fox over
  • Return
  • Take goose over

See here on ways to solve these puzzles.

48 questions
12
votes
10 answers

Another river with some extra letters

2 men are at a river. There is a boat. It holds only one person at a time. They both cross the river and continue their way... How? P.S. No Uber, helicopters, bridges, ropes, or anything else close by and the river isn't swimmable.
Heiko Hatzfeld
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10
votes
2 answers

What is the maximum number of items in a river crossing puzzle?

A River Crossing puzzle puts limits on the number of items that may cross a boundary, with limits on what may be left together. The "Fox, goose and bag of beans" is one of the earliest examples. Of course, by increasing the capacity of the boat, or…
James Jenkins
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8
votes
2 answers

Numbers nonexistent

This problem is one of the hardest problems I have ever encountered. If you don't trust links, here it is: There are some Couples wanting to cross a river by a boat. The boat can carry at most 3 persons at a time and of course cannot cross the…
bleh
  • 3,625
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  • 33
7
votes
2 answers

Cross the river with a small (4 spaces) boat

Giant, Slimy, Boy, Romy and Fatty want to cross a river. To cross the river there is a small boat. The boat only has 4 spaces. Every one can row the boat. At the boat, Giant needs 4 spaces. Slimy only needs 1 space, Boy also only needs 1 space. Romy…
Jamal Senjaya
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4
votes
1 answer

Family river-crossing

A family of six is crossing a river with a 2-passenger boat. The family includes the following members: Dad, Mom, Maid, Boy, Girl & Dog. Only the 3 adults can row the boat and the dog counts as a passenger. The dog will bite if the maid is not…
FANワンピース
  • 41
  • 1
3
votes
1 answer

Rigorous way to solve the river crossing problem

I encountered this classic brain teaser: Four people, A, B, C and D need to get across a river. The only way to cross the river is by an old bridge, which holds at most 2 people at a time. Being dark, they can't cross the bridge without a…
Victor
  • 131
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2
votes
2 answers

A river crossing puzzle

Here is a puzzle I came up with. Ali and Billie are approaching a river from one side, and Casey and Devin from the other side. Ali shouts: "Do you two also want to cross?" Casey shouts back: "Yes! This should be no problem, there is plenty of boats…
Falk Hüffner
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1
vote
2 answers

Crossing The River (Humans And Monsters Puzzle With A Twist)

3 couples on one side of a river. Aa Bb Cc (caps representing husbands, lowercase representing wives) One boat in which 2 people can travel at a time. At least one person must row the boat wherever it needs to be taken. The boat cannot travel to any…
Youstay Igo
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0
votes
1 answer

Strait-Crossing Puzzle

You are on an island, and must transport 3 moose across a strait to the mainland. While they can swim across the strait, they will likely end up running into the forest and leaving you behind. While you have a boat, it would be dangerous to try and…
Ichthys King
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-1
votes
1 answer

A Fox, a Chicken, a Pile of Seeds, and a Boat

There's 2 islands, 1 island has a pile of seeds, a chicken, and a fox. There's also a boat next to this island, you have to get it all across with minimum uses of the boat. You can only take one thing across at once. If you leave the fox and the…
warspyking
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-1
votes
1 answer

A man, a chicken, and a fox?

A man lives in a small house with a farm as his back garden and has a river beside his house. On the other side of the river is a shop. One day, he visited the shop, he bought a chicken and a fox for his farm and bought a bag of corn to feed the…
Jax
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-4
votes
1 answer

Ancient mysteries of the Arab world

If we want to convey the lion and the sheep and feed from the bank of the river to the other how to do it? and the lion will not eat the sheep and the sheep will not eat the feed
Mohammad
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