Two persons among Taro, Jiro and Hanako have dog and two persons have cat.
There is no one who has neither dog nor cat.
Those who have the dog are liar.
It cannot be said that the person who does not have dog is a honest person.
Taro said "Jiro has cat."
Jiro said "Hanako has cat."
What do they have, respectively?
Answer
Taro has cat only.
Jiro has dog and cat.
Hanako has dog only.
Solution
Supposing Taro's remark is a lie, Taro has dog and Jiro has dog and is a liar.
Thus, Hanako has dog from Jiro's remark.
It comes to that three persons have dogs which is contradictory.
Therefore, Taro's remark is true and Taro has cat and Jiro has cat.
If Jiro's remark is true, Hanako has cat.
Then three persons have cat and it is contradictory.
Therefore, Jiro is a liar and also has dog.
Hanako does not have cat but dog.
There is no one who has neither dog nor cat.
Those who have the dog are liar.
It cannot be said that the person who does not have dog is a honest person.
Taro said "Jiro has cat."
Jiro said "Hanako has cat."
What do they have, respectively?
Answer
Taro has cat only.
Jiro has dog and cat.
Hanako has dog only.
Solution
Supposing Taro's remark is a lie, Taro has dog and Jiro has dog and is a liar.
Thus, Hanako has dog from Jiro's remark.
It comes to that three persons have dogs which is contradictory.
Therefore, Taro's remark is true and Taro has cat and Jiro has cat.
If Jiro's remark is true, Hanako has cat.
Then three persons have cat and it is contradictory.
Therefore, Jiro is a liar and also has dog.
Hanako does not have cat but dog.
