Exercise #1


1. Use Venn diagram to test the validity of the following arguments.

1. Nuttinee loves dogs.
Anyone who loves dogs does not like cats.
Therefore, Nuttinee does not like cats.

2. Some BBA students belong to the Students' Government.
All members of the Students' Government are politically left-wing.
Therefore, all BBA students are politically left-wing.

3. People from Trang always vote for Chuan.
Chade always votes for Chuan.
So Chade is from Trang.

4. Not all students wear uniforms to school.
Therefore, some BBA students are disrespectful of the authorities,
because any student who does not wear uniform to school is disrespectful of the authorities.

5. Thailand is a pet of the West.
This is so because any country that blindly follows the West's lead is their pet,
and Thailand has been blindly following the West.

6. Genetically modified food is not dangerous.
This is so because humans have consumed it for a long time,
and anything that humans have consumed for a long time is not dangerous.

7. All attempts to alter the way nature works will bring harmful results.
Genetically modified food is a way of altering nature.
Therefore, genetically modified food will bring harmful results.

8. Most Thais who say they will vote for Taksin are tired of Chuan.
All Thais who are tired of Chuan don't like his policies.
Therefore, all Thais who say they'll vote for Taksin don't like Chuan's policies.

9. All Thais who say they will vote for Taksin are tired of Chuan.
Some Thais who are tired of Chuan actually like his policies.
Therefore, some Thais who say they'll vote for Taksin like Chuan's policies.

10. Most logic professors are fond of teaching.
Some teachers who are fond of teaching are good at it.
Hence, some logic professors are good at teaching.

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