1.So far, no one has ever swum the Atlantic Ocean non-stop or even come remotely close to
doing so. It is unlikely in the extreme, therefore, that anyone taking this test will swim the
Atlantic Ocean non-stop.
Deductive
Inductive
2.All inductive generalizations are inductive. Some inductive generalizations are unreliable.
Therefore, some inductive arguments are unreliable.
Deductive
Inductive
3.Tiger Woods is one of the best golfers in the world. Melvin Rumsley has never played golf in
his life. It is certain, therefore, that Melvin Rumsley could never beat Tiger Woods in a round
of golf.
Deductive
Inductive
4.Yale is an Ivy League school, and it has a good library. Harvard is an Ivy League school, and it
has a good library. Therefore, because Brown is an Ivy League school, it must have a good
library, too. (argument from analogogy)
Deductive
Inductive
5. All mosquitoes are insects. All insects are animals. So, all mosquitoes are animals.
(Knowledge  dung/sai cua statement)
Sound
Unsound
6. If Rome is in Italy, then Rome is in Europe. Rome is in Italy. So, Rome is in Europe.
Sound
Unsound
7. Halloween is always on a Friday (wrong). Therefore, the day after Halloween is always a
Saturday. (wrong)
Sound
Unsound
8. All birds can fly. Penguins are birds. So, penguins can fly (Conclu có liên quan chặt chẽ vs
premises ko, có thì là deductive, ko là inductive)
Valid khi true premises  false conclusion ( T  T, FT)
Invalid khi false premises  false conclusion
Deductive, invalid
Deductive, valid
Inductive, weak
Inductive, strong
9. Most college students sleep late on Sunday mornings. Wes is a college student. So, Wes
probably sleeps late on Sunday mornings.
Deductive, invalid
Deductive, valid
Inductive, weak
Inductive, strong
CHAP 9: VENN DIAGRAM
1. Some dot-com millionaires (D) are philanthropists (P). All philanthropists are altruists
(A). Hence, some altruists are dot-com millionaires.
Valid
Invalid
2. Some telemarketers (T) are Methodists (M). Some Methodists are Democrats (D). So, some
Democrats are telemarketers. (3 some  invalid)
Valid
Invalid
3.No beach bums are workaholics. Some beach bums are rollerbladers. So, some rollerbladers
are not workaholics.
Valid
Invalid
4. All violinists are musicians. Therefore, since some bookworms are violinists,nsome
bookworms are musicians.
Valid
Invalid
5. All ecologists are environmentalists. Hence, because all ecologists are wilderness-lovers, all
wilderness-lovers are environmentalists.
Valid
Invalid
6. All meteorologists are forecasters. Hence, because some forecasters are psychics, some
psychics are meteorologists.
Valid
Invalid