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: I. All grills are ovens. II. Some tandoors are grills. Conclusions: I. Some tandoors are oven. II. All ovens are tandoor.
Only conclusion I follows.
Understanding Statements and Conclusions in Logic
This question presents a classic logic puzzle involving statements and conclusions. Our task is to carefully read the given statements, assume they are absolutely true, and then determine which of the provided conclusions are logically guaranteed by those statements.
Analyzing the Given Statements
We are given two core statements:
- Statement I: All grills are ovens.
- Statement II: Some tandoors are grills.
Let's break down what these statements mean:
- Statement I establishes a relationship where the entire category of 'grills' is included within the category of 'ovens'. If something is a grill, it must also be an oven.
- Statement II establishes an overlap between the categories of 'tandoors' and 'grills'. There is at least one item that belongs to both the 'tandoor' category and the 'grill' category.
Evaluating the Conclusions Based on Statements
Now we examine each conclusion to see if it necessarily follows from the statements.
Conclusion I: Some tandoors are oven.
Let's trace the connection using the statements:
- From Statement II, we know that there are some members of the 'tandoor' group that are also in the 'grill' group. Let's call one such member 'X'. So, X is a tandoor and X is a grill.
- From Statement I, we know that all members of the 'grill' group are also in the 'oven' group. Since X is a grill (from Statement II), it must also be an oven.
- Therefore, X is a tandoor and X is an oven. This confirms that there is at least one member (X) that is both a tandoor and an oven.
This logically leads to the conclusion that some tandoors are ovens. Thus, Conclusion I follows from the given statements.
Conclusion II: All ovens are tandoor.
Let's consider this conclusion carefully:
- Statement I tells us that the set of grills is a subset of the set of ovens. This means the 'ovens' group is at least as large as the 'grills' group and contains all grills.
- Statement II tells us some tandoors are grills. Combined with Statement I, this tells us some tandoors are ovens (as we proved for Conclusion I).
However, the statements do not provide any information about whether all ovens are tandoors. There might be many types of ovens that are not grills. The statements do not say whether these non-grill ovens are tandoors or not. For Conclusion II ("All ovens are tandoor") to be true, every single item in the 'oven' category would need to also be in the 'tandoor' category.
We can imagine a scenario where the statements are true, but Conclusion II is false. For example:
- Statements: All grills are ovens. Some tandoors are grills.
- Scenario: Grills = {A, B}. Ovens = {A, B, C, D}. Tandoors = {A, E}.
In this scenario:
- Statement I: All grills {A, B} are in ovens {A, B, C, D}. True.
- Statement II: Some tandoors {A, E} are grills {A, B}. They share A. True.
- Conclusion I: Some tandoors {A, E} are ovens {A, B, C, D}. They share A. True.
- Conclusion II: All ovens {A, B, C, D} are tandoors {A, E}. This is False, as C and D are ovens but not tandoors.
Since we found a valid scenario where the statements hold true but Conclusion II is false, Conclusion II does not logically follow from the statements.
Which Conclusion Logically Follows?
Based on our analysis:
- Conclusion I (Some tandoors are oven) is logically derived from the statements.
- Conclusion II (All ovens are tandoor) is not logically derived from the statements.
Therefore, only Conclusion I follows.
Revision Table: Logical Reasoning Basics
| Term | Meaning in Syllogisms | Example Relation |
|---|---|---|
| All A are B | A is a subset of B. | Every item in category A is also in category B. |
| Some A are B | There is at least one item common to A and B. | Categories A and B have an overlap. |
| Logically Follows | The conclusion must be true whenever the statements are true. | A deduction that is necessarily valid. |
Additional Information: Deductive vs Inductive Reasoning
This question uses deductive reasoning, which is common in logic tests. Deductive reasoning starts with general statements (premises) and reaches a specific conclusion that is certain if the premises are true. Syllogisms are a form of deductive reasoning.
In contrast, inductive reasoning starts with specific observations and arrives at a general conclusion that is probable but not certain. For instance, observing many white swans and concluding "All swans are white" is inductive (and can be proven false by finding a black swan).
For statements and conclusions questions, focus solely on deductive validity. Does the conclusion *have* to be true if the statements are true? If yes, it follows. If not (if you can imagine a scenario where statements are true but the conclusion is false), it does not follow.
Important Questions from Conventional Syllogism
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:
1. Some flowers are chemicals.
2. Some chemicals are herbs.
Conclusions:
I. No flower is a herb.
II. Some flowers are herbs.
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 students are teachers.
All teachers are professors.
Conclusions:
1. All students are professors.
2. All professors are students.
3. No teacher is a professor.
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:
I. Some dentists are surgeons.
II. All the surgeons are doctors.
Conclusions:
I. Some dentists are doctors.
II. No surgeons are dentists.
The statements below are followed by two conclusions labelled I and II. Assuming that the information in the statements is true, even if it appears at variance with generally established facts. decide which conclusion(s) logically and definitely follow(s) from the information given in the statements.
Statements:
1) Some angers are griefs.
2) Some griefs are loves.
Conclusion:
I. Some griefs are angers.
II. Some loves are griefsThe statements below are followed by two conclusions labeled I and II. Assuming that the information in the statements is true, even if it appears to be at variance with generally established facts. decide which conclusion(s) logically and definitely follow(s) from the information given in the statements.
Statements:
Some cows are deer.
Some deer are fishes.
Conclusion:
I. Some cows are fishes.
II. Some fishes are cows.
