Construct truth trees for the following arguments, then indicate whether the truth tree shows that the argument is deductively valid. (13 points each.)
| 1. |
~P
 ~Q |
2. |
R
(Q P) |
|
|
R
 P |
~Q
~P |
|||
 |
|
|||
|
R
|
R
|
|||
|
|
||||
| 3. |
P
(Q
R) |
4. |
P
 ~Q |
|
|
Q
~R |
~P
|
|||
|
|
|
|||
|
P
|
Q
|
|||
|
|
|
In each of the following, construct a Venn diagram and use it to answer the question. (12 points each.)
| 5. All Chemists are scientists. No astrologers are scientists. So no chemists are astrologers. Is this argument valid? |  |
|
6. Only humans are vampires. All humans are mortal. All vampires are immortal. So there are no vampires. Is this argument valid? |
|
| 7. José and Pedro are Argentines, but only Pedro is a Patagonian. Some Patagonians are gauchos. Is José a gaucho? | |
|
8. Only birds are ratites. Some ratites inhabit New Zealand. Do any birds inhabit New Zealand? |
|
Page last
updated:
Send email to Donald Nute