Read the statements and answer the question based on it. Statements: 1. Some mammals are extinct and some are critically endangered. 2. All dinosaurs are extinct. 3. Some reptiles are critically endangered and some are already extinct. Which option logically follows the given statements? A. All dinosaurs are mammals B. There are no reptiles that are out of the danger of extinction. C. No dinosaurs are critically endangered.
C
Understanding Logical Reasoning Statements
This question requires us to carefully read the given statements and determine which of the options can be logically concluded based only on the information provided in those statements. We must not use any outside knowledge, even if it seems true, unless it is explicitly stated or directly implied by the statements.
Analyzing the Given Statements
Let's break down each statement:
- Statement 1: Some mammals are extinct and some are critically endangered.
- This tells us that within the group 'mammals', there are some that are extinct and some that are critically endangered.
- It also implies that there are mammals that are neither extinct nor critically endangered (i.e., living mammals that are not currently considered critically endangered).
- Statement 2: All dinosaurs are extinct.
- This is a strong, universal statement. Every single entity classified as a 'dinosaur' no longer exists.
- Statement 3: Some reptiles are critically endangered and some are already extinct.
- Similar to Statement 1, this indicates that within the group 'reptiles', some fall into the category of critically endangered and some fall into the category of extinct.
- It also implies that there are reptiles that are neither critically endangered nor extinct (i.e., living reptiles that are not currently considered critically endangered).
Evaluating Each Option
Now let's examine each option and see if it logically follows from the statements:
Option A: All dinosaurs are mammals
- Statement 2 says all dinosaurs are extinct. Statement 1 says some mammals are extinct, but not all mammals are extinct.
- The statements treat dinosaurs and mammals as separate categories. There is nothing in the statements that suggests a dinosaur is a type of mammal or that all dinosaurs belong to the mammal group.
- Therefore, this option does not logically follow.
Option B: There are no reptiles that are out of the danger of extinction.
- Statement 3 says "Some reptiles are critically endangered and some are already extinct."
- This wording ("some... and some...") implies that these are specific subsets within the group of reptiles. It does not say "All reptiles are either critically endangered or extinct."
- If some reptiles are critically endangered or extinct, it naturally suggests that there might be other reptiles that are not in these specific categories of danger (i.e., they are 'out of the danger of extinction' based on the categories mentioned).
- Therefore, the statement "There are no reptiles that are out of the danger of extinction" directly contradicts the implication of Statement 3. This option does not logically follow.
Option C: No dinosaurs are critically endangered.
- Statement 2 says "All dinosaurs are extinct."
- The definition of 'extinct' means that a species no longer exists.
- The term 'critically endangered' applies to species that are currently living but face an extremely high risk of extinction in the wild.
- If all dinosaurs are extinct (meaning they don't exist), then it is impossible for any dinosaur to be currently living and facing the risk of extinction. Therefore, no dinosaurs can be critically endangered.
- This option is a direct logical consequence of Statement 2. This option logically follows.
Option D: Some reptiles are dinosaurs who are extinct.
- Statement 2 says "All dinosaurs are extinct."
- Statement 3 says "Some reptiles are critically endangered and some are already extinct."
- While it is true in biology that dinosaurs are related to reptiles (or are considered a group within reptiles depending on classification), the given statements do not explicitly state this relationship.
- Statement 2 defines the status of *all* dinosaurs. Statement 3 defines the status of *some* reptiles. The statements, taken strictly as given, do not force the conclusion that the "some reptiles who are already extinct" mentioned in Statement 3 *must* be dinosaurs. Dinosaurs are extinct according to Statement 2, and some reptiles are extinct according to Statement 3. These could, logically, be two separate groups based *only* on the information provided.
- The question asks what *logically follows* from the statements. Option C follows directly and undeniably from Statement 2. Option D requires an assumption about the relationship between reptiles and dinosaurs that is not explicitly stated in the premises.
- Therefore, based strictly on the logic of the statements, this option does not necessarily follow.
Conclusion
Based on the logical analysis of the statements, Option C is the only conclusion that is directly and undeniably supported by the provided information, specifically Statement 2.
| Statement | Key Implication |
|---|---|
| 1. Some mammals are extinct and some are critically endangered. | Mammals exist and are divided into statuses like extinct, critically endangered, and likely others (not in these categories). |
| 2. All dinosaurs are extinct. | Dinosaurs no longer exist. |
| 3. Some reptiles are critically endangered and some are already extinct. | Reptiles exist and are divided into statuses like critically endangered, extinct, and likely others. |
| Option | Logical Analysis based on Statements | Follows? |
|---|---|---|
| A. All dinosaurs are mammals | Statements don't link dinosaurs and mammals this way. Statement 2 says all dinosaurs extinct; Statement 1 says only *some* mammals extinct. | No |
| B. There are no reptiles that are out of the danger of extinction. | Statement 3 says *some* are in danger categories, implying others are not. Contradicts the statement. | No |
| C. No dinosaurs are critically endangered. | Statement 2 says all dinosaurs are extinct. If extinct, they don't exist, so they cannot be critically endangered (which applies to living species). | Yes |
| D. Some reptiles are dinosaurs who are extinct. | Statements don't explicitly state dinosaurs are a subset of reptiles. While biologically true, not logically necessary from *these* statements. | No (Based *strictly* on the statements) |
Revision Table: Statement Analysis
Let's quickly review the core implications:
- Extinct: Species no longer exists.
- Critically Endangered: Species currently exists but is at extremely high risk of becoming extinct.
- Statement 2: All dinosaurs = Extinct. This is the critical point for option C.
Additional Information: Logic and Set Theory Basics
Logical reasoning questions often test your ability to understand relationships between categories or sets based on given rules (statements). Key terms include:
- All: Refers to every member of a set. If "All A are B," then if something is an A, it must also be a B.
- Some: Refers to at least one, and possibly all, members of a set. If "Some A are B," it means there is at least one A that is also a B. It does not mean *only* some are B, nor does it imply that some A are *not* B (though that is often the practical implication unless "All A are B" is also stated).
- No: Refers to zero members of a set. If "No A are B," then if something is an A, it cannot be a B. Equivalently, if something is a B, it cannot be an A.
In this question, Statement 2 uses "All" and Statement 3 uses "Some". Understanding the implications of "All dinosaurs are extinct" is key. If they are all extinct, the set of "dinosaurs" has no members currently existing, thus no members can be in the set of "critically endangered" species (which must exist). This aligns with option C.
Important Questions from Statements and Conclusions
In the following question below are given some statements followed by some conclusions based on those statements. Taking the given statements to be true even if they seem to be at variance from commonly known facts. Read all the conclusions and then decide which of the given conclusion logically follows the given statements.
Statements:
I. All A are B.
II. Some B are C.
Conclusions:
I. Some A are C.
II. Some A are not C.
III. Some A are B.
Read the given statements and conclusions carefully and decide which of the given conclusions logically follows from the given statements.
Statement:
A asked C, "What time is it now?" Is it half past two? ''
Conclusions:
1. A wants to go to lunch.
2. A wants to confirm what the time is because his watch is off.
In the question one statement is given, followed by two conclusions, I and II. You have to consider the statements to be true even if it seems to be at variance from commonly known facts. You have to decide which of the given conclusions, if any, follows from the given statements.
Statement : 55% of Manisha's office colleagues went to watch the movie.
Conclusion I : Manisha went to watch the movie.
Conclusion II : Manisha did not go to watch the movie.
In the question two statements are given, followed by two conclusions, I and II. You have to consider the statements to be true even if it seems to be at variance from commonly known facts. You have to decide which of the given conclusions, if any, follows from the given statements.
Statement 1 : All schools are books.
Statement 2 : No books are papers.
Conclusion I : No schools are books.
Conclusion II : Some books are schools.
In the question below are given some statements followed by some conclusions based on those statements. Take the given statements to be true even if they seem to be different from commonly known facts. Read all the conclusions and then decide which of the given conclusions logically follows from the given statements.
Statements:
I. Some P are Q.
II. All P are N.
Conclusion:
I. All Q are N.
II. Some P are not Q.
