Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements. Statement I: All males are females. Statement II: Some females are old. Conclusion I: All males are old. Conclusion II: Some males are old.
Neither I nor II follows
This problem requires us to carefully analyze the given statements and determine which of the provided conclusions logically follow from them, assuming the statements are absolutely true, regardless of common knowledge.
We have two statements:
In logical reasoning, statements of the form 'All A are B' mean that the set of A is entirely contained within the set of B. Statements of the form 'Some A are B' mean there is at least one element common to both sets A and B, or the intersection of sets A and B is not empty.
Conclusion I: All males are old. (Represented as All M are O)
Let's consider if this conclusion must be true based on the statements:
However, the fact that some females are old does not guarantee that the females who are old are also males. The group of females who are old could be females who are not males. Since the set of males is entirely within the set of females, but the 'old' group only partially overlaps with females, there is no logical necessity for the 'old' group to overlap with the 'males' group at all.
Therefore, Conclusion I, "All males are old," does not logically follow from the given statements.
Conclusion II: Some males are old. (Represented as Some M are O)
Let's consider if this conclusion must be true based on the statements:
This is similar to the reasoning for Conclusion I. We know there are some females who are old. These females could be males (since all males are females), or they could be females who are not males. Since the statements do not provide any information that forces the 'some females who are old' group to include any individuals from the 'males' group, we cannot definitively say that there is an overlap between males and old people.
The statements allow for a scenario where all males are females, some females are old, but none of the males are among the females who are old. For example, if females are {Alice, Betty, Carol, David, Eve}, males are {David, Eve} (so all males are females), and old are {Alice, Betty} (so some females are old). In this case, no males (David, Eve) are old (Alice, Betty).
Therefore, Conclusion II, "Some males are old," does not logically follow from the given statements.
Based on our analysis of the statements:
Thus, neither of the given conclusions logically follows from the statements.
| Statement Type | Form | Meaning |
|---|---|---|
| Universal Affirmative | All A are B | Every element of A is an element of B. Set A is a subset of Set B. |
| Universal Negative | No A are B | No element of A is an element of B. Sets A and B are disjoint. |
| Particular Affirmative | Some A are B | At least one element of A is an element of B. The intersection of Sets A and B is not empty. |
| Particular Negative | Some A are not B | At least one element of A is not an element of B. There exists an element in Set A that is not in Set B. |
This problem is a form of syllogism, which is a type of logical argument that applies deductive reasoning to arrive at a conclusion based on two or more propositions that are asserted or assumed to be true. A simple syllogism has three parts: a major premise, a minor premise, and a conclusion.
In a valid syllogism, the conclusion must necessarily be true if the premises are true. In the given problem, the structure of the premises ("All M are F," "Some F are O") does not guarantee a relationship between M and O, making the potential conclusions ("All M are O," "Some M are O") not logically follow.
Understanding the rules of valid syllogisms and how different types of statements relate sets (often visualized with Venn diagrams) is crucial for solving such logic problems. The middle term (Females in this case) connects the two premises but doesn't automatically transfer properties from one extreme term (Males) to the other (Old).
Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.
Statements:
All dancers are talented.
Some girls are dancers.
Conclusions:
I. Some girls are talented.
II. All talented are girls.
III. All girls are talented.
Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.
Statements:
All directors are actors.
No actor is a producer.
All choreographers are directors.
Conclusions:
I. No choreographer is producer.
II. Some actors are choreographers.
III. No director is a producer.
Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follows from the statements.
Statements:
All lemons are plums.
All plums are dates.
Some dates are mangoes.
Conclusions:
I. Some lemons are mangoes.
II. Some mangoes are plums.
III. All lemons are dates.
IV. Some mangoes are dates.
Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.
Statements:
Some cards are postcards.
Some cards are envelopes.
All envelopes are copies.
Conclusions:
I. Some copies are envelopes.
II. Some postcards are copies.
III. Some cards are copies.
Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.
Statements:
All employees are tax-payers.
Some employees are farmers.
Some farmers are doctors.
Conclusions:
I. No farmer is a tax-payer.
II. Some farmers are tax-payers.