Which of the following is contrary to the statement "No mammals are birds"?
All mammals are birds.
Concept: In the classical Square of Opposition, two universal propositions with the same subject and predicate but opposite quality are contraries. The universal negative (E) 'No S are P' and the universal affirmative (A) 'All S are P' are contraries: they cannot both be true at the same time, though both could be false.
Working: The given statement 'No mammals are birds' is an E-type proposition (S = mammals, P = birds). Its contrary is formed by keeping the same subject and predicate but changing the quality from negative to affirmative and keeping it universal, giving the A-type 'All mammals are birds'. These two cannot be true together, which is exactly the contrary relation.
Why the other choices are wrong:
'No birds are mammals' is simply the converse of the original and is logically equivalent to it, not opposed to it.
'Some mammals are birds' is the particular affirmative (I); it is the contradictory of the original, not its contrary.
'Some birds are mammals' is a particular affirmative about the reversed classes and is the contradictory of the converse, again not the contrary of the given statement.
Takeaway: The contrary of a universal negative is the corresponding universal affirmative.
Correct answer: All mammals are birds.
Similar Questions
In a square of opposition, if 'No animals with horns are carnivores' is false, which of the following is the correct code?
codes:
A. 'Some animals with horns are carnivores' is true.
B. 'Some animals with horns are not carnivores' is true.
C. 'All animals with horns are carnivores' is false
D. 'All the animals with horns are carnivores' is undermined.Which of the following statements are logically equivalent?
A. Some cricketers are kind men.
B. Some kind men are cricketers.
C. Some cricketers are not non-kind men.
D. Some non-kind men are not non-cricketers.
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Which of the following statements is contradictory to the statement - "Some birds are mammals"?
If the statement - "Some animals are not birds" is given as false, then which of the following statements can be immediately inferred to be false?
If the statement "Some animals are birds" is given as false then which of the following statements can be immediately inferred to be false?
Which of the following propositions can be directly inferred from the statement - "All mammals are four-legged animals?
Which of the following statements are contradictory to each other?
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C. Some objects are perishable.
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Which of the following statements is contradictory to the statement-" all dogs are friendly animals" ?
Important Questions from Classical Square of Opposition
Which of the following statements are so related that they can not both be true but could both be false?
A. All Biologists are outstanding teachers.
B. Some Biologists are outstanding teachers.
C. No Biologists are outstanding teachers.
D. Some Biologists are not outstanding teachers.
Choose the correct answer from the options given below:
- Which of the following propositions are so related that they can neither be true together nor can they be false together?
A. All printers are computer peripherals.
B. Some computer peripherals are printers.
C. Some printers are not computer peripherals.
D. No printers are computer peripherals.
Choose the correct answer from the options given below: - Which of the following statements contradict each other ?
A. All ducks are birds.
B. Some ducks are birds.
C. Some ducks are not birds.
D. No ducks are birds.
Choose the most appropriate answer from the options given below : - If the statement "No birds are animals" is given as false, which of the following statements can be inferred to be true ?
A. Some animals are not birds.
B. Some birds are not animals.
C. Some animals are birds.
D. Some birds are animals.
Choose the most appropriate answer from the options given below : - Which of the following statements are sub-contraries?
A. All sparrows are birds.
B. No sparrows are birds.
C. Some sparrows are birds.
D. Some sparrows are not birds.
Choose the correct answer from the options given below:
