For each syllogism, declare whether it is valid or invalid according to the rule
ID: 3492655 • Letter: F
Question
For each syllogism, declare whether it is valid or invalid according to the rules presented. If the syllogism is invalid, indicate which rule it breaks:
1 There must be three terms and only three terms.
2 The middle term must be distributed at least once.
3 No term may be distributed in the conclusion if it was not distributed in the premise.
4 No conclusion may be drawn from two negative premises.
5 If one of the premises is negative, the conclusion must be negative.
6 No particular conclusion may be drawn from two universal premises (and vice versa).
A) No planets are suns. No planets are satellites. Therefore, no satellites are suns.
B) All cosmonauts are highly trained men. Some test pilots are not highly trained men. Therefore, some cosmonauts are not test pilots
C)All A is B. Some B is C.Therefore, some C is A
D)Some A is B. All B is C. Therefore, some C is A
E)Anything I possess is mine. I possess your pen. Therefore, your pen is mine.
F)All contracts are based upon an agreement between two parties. The United Nations is based upon an agreement between several countries. Therefore, the United Nations can also be classified as a contract.
G) Because most Americans are industrious and all of them love freedom, most industrious people love freedom.
H)Since robins are two legged creatures and since all birds are two-legged creatures, it follows that all robins are birds.
I)Since only radicals want to subvert the duly constituted government of the country, this man can't be a radical because he wants to preserve the government of the country.
J)Prabusks are certainly not panbuls. I know that because plocucks are panbuls and prabusks are plocucks.
Explanation / Answer
A) No planets are Suns. No planets are satellites. Therefore , no satellites are Suns.
Invalid , no conclusion may be drawn from two negative premises ., both first & second premises are negative.
B) All cosmonauts are highly trained men. Some test pilots are not highly trained. Therefore some cosmonauts are not test pilot.
Invalid , if one of the premises is negative the conclusion must be negative ., the second premise is negative hence having a negative conclusion
C) All A is B . Some B is C. Therefore some C is A
Valid
D) Some A is B. All B is C. Some C is A
Valid
E) Anything I possess is mine. I possess your pen. Therefore your pen is mine.
Valid
F) All contracts are based upon an agreement between two parties. The United Nations is based upon an agreement between several countries. Therefore the United Nations can also be classified as a contract.
Invalid ., no term may be distributed in the conclusion if it is not distributed in the premise.
G) Because most Americans are industrious and all of them love freedom, most industrious people love freedom
Invalid, there must be 3 terms & only 3 terms.
H) since robins are two legged creatures and since all birds are two legged creatures, it follows that all robins are birds.
Invalid , no particular conclusion may be drawn from 2 universal premises.
I) Since only radicals want to subvert the duly constituted government of the country , this man can't be a radical because he wants to preserve the government of the country.
Invalid , no term may be distributed in the conclusion if it was not distributed in the premise.
J) Prabusles are certainly not pan us. I know that because plocucks are pan us and Prabusles are plocucks.
Invalid , the term must be distributed at least once & there must be 3 terms.
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