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The Sick Dog and the Flower

Logic puzzles require you to think. You will have to be logical in your reasoning.


Puzzle ID:#12710
Fun:*** (2.54)
Difficulty:*** (2.69)
Submitted By:kvakk**
Corrected By:shenqiang




Hi, my name is mister Kvakk. I live in a very big house in the country. Outside my house I have a lot of very big gardens, and it is in one of these gardens my dog (which is also my best friend) lives. But although my dog is just a dog, it has also got the ability to think. And not just that, my dog is a really smart and rational dog too.

Unfortunately, the dog is not happy. It is infected by a virus. It feels ill. The doctor says it's a 50% chance that it will die, and a 50% chance that it will be fresh again.
But in this garden where my dog lives, I have also a lot of plants. Some days ago, I put a new seed in my garden. The seed will grow up to a beautiful, red flower. So delicious will the flower be, that my dog really will want to eat it when it has grown up (yes, my dog eats flowers). But the flower is even more wonderful. If my dog eats this flower, this will kill every virus in it, and the dog will survive.

But this flower is also a very special kind of plant, because it has the ability to think too. And it is completely rational. It knows that my dog will want to eat it one day later. Therefore, the flower has the option to develop a weapon: At any time it may start to develop poison. If my dog is so unlucky to eat a flower full of poison, it will surely die, which, of course, it doesn't want to. So if the flower decides to develop poison, it's best for the dog not to eat it.
But the poison development is not an easy task to do for the flower. It doesn't want to make poison just to make poison. If it could avoid developing poison, it wouldn't do it. But, of course, the flower would like to live too, and it's better for it to develop poison than to be eaten by the dog.

Unfortunately, there is no way for the dog to see or know whether the flower has decided to develop poison or not. Both the dog and the flower know this. The dog knows, however, that the flower is just as rational as itself. The dog knows that the flower has the option to make poison, and the dog knows that the creation of poison is a hard task to do for the flower, and that it will only do it if it can save its life. In the same way, the flower knows that my dog is completely rational. My dog also knows that the flower cares only about itself. Whether the dog dies or not is irrelevant to the flower. No other red flowers will ever grow in this garden.

Let's sum up the assumptions:

1. The flower is rational and wants to make its own life as good as possible.
2. The flower knows that the dog is rational.
3. The flower doesn't want to die.
4. The flower doesn't care about what will happen to the dog.
5. The flower doesn't want to make poison. It's a hard task to do.
6. But the flower will make poison if that could prevent the dog from eating it.
7. The dog is rational.
8. The dog knows that the flower doesn't care about whether the dog dies or not.
9. The dog doesn't want to die.
10. The dog knows that the flower is rational (there is no uncertainty at this point, it knows it for sure).
11. The dog knows that the flower will make poison if that could prevent the dog from eating it.
12. The dog cannot see or know whether the flower actually makes poison or not.
13. The dog knows that the flower knows that the dog cannot see or know this.
14. If the dog eats a flower without poison it will survive. If it is poisonous it will die.
15. If the dog doesn't eat the flower, it is a 50 % chance that it will die.

So now, the question is: Will the dog eat the flower? Why or why not?

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