If the statement-"Some athletes are kind human beings" is given as true, then which of the following statements can be immediately inferred to be false?
No athletes are kind human beings.
This question also uses the Square of Opposition. The given true statement, "Some athletes are kind human beings", is a particular affirmative (I-type) statement.
In the square of opposition, every I-type statement has a corresponding E-type (universal negative) statement with the same subject and predicate, and these two are called CONTRADICTORIES. A key rule of contradictories is: they can never have the same truth value — if one is true, the other MUST be false, and vice versa.
The E-type statement corresponding to "Some athletes are kind human beings" is "No athletes are kind human beings" (Option 3).
Since the given I-type statement is true, its contradictory E-type statement must necessarily be false. So Option 3, "No athletes are kind human beings," is the statement that can be immediately inferred to be false.
Let's check why the other options cannot be immediately determined as false:
- Option 1, "Some athletes are not kind human beings" (O-type), is the subcontrary of the given I-type statement. When an I-type statement is true, its subcontrary can be either true or false — it is not fixed, so we cannot say it is false.
- Option 2, "All athletes are kind human beings" (A-type), is the super-altern of the given I-type statement. Truth of the I-type statement does not guarantee the truth or falsity of the A-type statement — it remains undetermined.
- Option 4, "Some kind human beings are athletes," is simply the valid simple conversion of the given true I-type statement, so it is actually TRUE, not false.
Hence, only Option 3 — No athletes are kind human beings — must be false
Which of the following is contrary to the statement "No mammals are birds"?
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?
A. All objects are perishable.
B. Some objects are not perishable.
C. Some objects are perishable.
D. No objects are perishable.
Choose the most appropriate answer from the options given below:
If the statement 'No men are honest' is given as false, then which of the following could be immediately inferred from it?
A. 'All men are honest' is true
B. 'All men are honest' is undetermined
C. 'Some men are not honest' is true
D. 'Some men are honest' is true
Choose the correct answer from the options given below:
Given below are two statements
Statement I: Contrary statements are so related that if one of them is true, the other must be false.
Statement II: Contrary statements cannot both be false.
In light of the above statements, choose the correct answer from the options given below :
If the proposition ‘domestic animals are hardly ferocious’ is taken to be false, which of the following proposition/propositions can be claimed to be certainly true? Select the correct code:
Propositions:
(a) All domestic animals are ferocious.
(b) Most of the domestic animals are ferocious.
(c) No domestic animal is ferocious.
(d) Some domestic animals are non-ferocious.
Code:
Given below are four statements. Among them two are related in such a way that they can both be true but they cannot both be false. Select the code that indicates those two statements:
Statements:
(a) Honest people never suffer.
(b) Almost all honest people do suffer.
(c) Honest people hardly suffer.
(d) Each and every honest person suffers.
Code:
Among the following propositions two are related in such a way that they cannot both be true but can both be false. Select the code that states those two propositions.
Propositions:
(a) Every student is attentive.
(b) Some students are attentive.
(c) Students are never attentive.
(d) Some students are not attentive.
Codes:
If proposition 'some milk is curd' is taken to be true, then which of the following propositions can be false?
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: