Two statements are given followed by two Conclusions: Statements: 1. All cats are dogs. 2. All cats are black. Conclusion–I: 1. All dogs are black. Conclusion–II: 1. Some dogs are not black. Which of the above conclusions logically follow/s from the two given statements, disregarding commonly known facts?

IAS 2020 — CSAT Reasoning

2020mcqmedium

Two statements are given followed by two Conclusions:

Statements:

All cats are dogs.
All cats are black.

Conclusion–I:

All dogs are black.

Conclusion–II:

Some dogs are not black.

Which of the above conclusions logically follow/s from the two given statements, disregarding commonly known facts?

Official previous-year question

Verified 2 Aug 2026.

Options

AOnly Conclusion–I
BOnly Conclusion–II
CNeither Conclusion – I, nor Conclusion–II
DBoth Conclusion–I, and Conclusion–II

Did you get this right?

Solution

Correct Option (3)

Neither Conclusion – I, nor Conclusion–II

To determine which conclusions logically follow, we analyze the given statements:

Statement 1: All cats are dogs. (This implies that the set of cats is a subset of the set of dogs.)
Statement 2: All cats are black. (This implies that the set of cats is a subset of the set of black entities.)

Let's evaluate each conclusion:

Conclusion I: All dogs are black.

This conclusion does not necessarily follow from the statements. While all cats are black and all cats are dogs, the statements do not provide information about dogs that are not cats. It is possible to have dogs that are not cats, and these non-cat dogs could be of any color, including non-black. For example, consider a scenario where there are black cats (which are also dogs), and there are also brown dogs (which are not cats). In this scenario, Statement 1 and Statement 2 hold true, but Conclusion I (All dogs are black) is false. Therefore, Conclusion I is not a necessary deduction.

Conclusion II: Some dogs are not black.

This conclusion also does not necessarily follow. The given statements are consistent with a scenario where all dogs are black. For instance, if all dogs (including those that are cats and those that are not) happen to be black, then Statement 1 and Statement 2 would still be true, but Conclusion II (Some dogs are not black) would be false. Since we can construct a scenario where Conclusion II is false while the statements are true, it is not a necessary deduction.

Since neither Conclusion I nor Conclusion II can be definitively proven true based solely on the given statements, neither logically follows.

Incorrect Options:

Options 1, 2, and 4 are incorrect because, as explained above, neither Conclusion I nor Conclusion II can be logically deduced as necessarily true from the given statements. A conclusion logically follows only if it is true in all possible interpretations consistent with the premises. Since counter-examples can be found for both conclusions, they do not logically follow.

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Correct Option (3)

Neither Conclusion – I, nor Conclusion–II

To determine which conclusions logically follow, we analyze the given statements:

Statement 1: All cats are dogs. (This implies that the set of cats is a subset of the set of dogs.)
Statement 2: All cats are black. (This implies that the set of cats is a subset of the set of black entities.)

Let's evaluate each conclusion:

Conclusion I: All dogs are black.

Conclusion II: Some dogs are not black.

Since neither Conclusion I nor Conclusion II can be definitively proven true based solely on the given statements, neither logically follows.

IAS 2020 — CSAT Reasoning

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Solution

Correct Option (3)

Incorrect Options:

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Options

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Solution

Correct Option (3)

Incorrect Options:

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More IAS Reasoning questions

Other CSAT topics for IAS

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