Math Is Fun Forum

U7109

Real Member

Registered: 2007-03-19

Posts: 485

Canoe Solve This?

A woman wants to take a cat, a mouse and some cat food from one side of a river to another. She has one small canoe that can only hold one other thing besides her. If the cat and mouse are left alone, the cat will eat the mouse. If the cat is left alone with the cat food, it will eat it. How can the woman get all three things across the river safely?

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"Reality leaves a lot to the imagination," ~ John Lennon

TheDude

Member

Registered: 2007-10-23

Posts: 361

Re: Canoe Solve This?

First she takes the cat across the river.  Then she heads back and picks up the mouse and takes it across the river.  When she gets to the other side she puts the mouse down and picks the cat back up.  She goes back to the other side and leaves the cat while picking up the cat food.  She then takes the cat food to the other side of the river and leaves it with the mouse.  Finally, she goes back to pick up the cat and then takes it to the side with the mouse and cat food.

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Wrap it in bacon

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Canoe Solve This?

That's an interesting variation on the puzzle that I think is more common.
Usually, you'd have (for example) a cat, a mouse and some cheese.
Left alone, the cat would eat the mouse and the mouse would eat the cheese.

The solution is similar though because it doesn't matter what eats what, you just need to make sure that the problem pairs aren't left alone. Therefore, the mouse in this problem is equivalent to the cat in yours.

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Why did the vector cross the road?
It wanted to be normal.