“Sudhir had not locked the gates yesterday. Either the watchman or Sudhir locks the gates. Therefore, the watchman must have locked the gates yesterday”. This argument is ..................... .
Deductive and valid
Let W = the watchman locked the gates and S = Sudhir locked the gates. The argument is: W ∨ S; ~ S; therefore W.
This is the form of disjunctive syllogism (p ∨ q, ~ q, ∴ p). It claims that the conclusion follows necessarily from the premises, so it is a deductive argument.
The form is valid: in a truth table there is no row in which both premises are true and the conclusion false. If one disjunct is denied, the other must be true.
Since the argument claims necessity and has a valid form, terms like ‘inductive’, ‘good’ or ‘invalid’ do not apply.
Hence, the answer is Deductive and valid.
Similar Questions
Match List I and List II and select the correct answer from the codes given below :
List I List II (a) ~ (p ∨ ~ p) (1) Identity (b) ~ (p • ~ p) (2) Contingency (c) ~ (p ⊃ q) (3) Tautology (d) p ⊃ p (4) Contradiction Codes :
(a) (b) (c) (d)
Which of the following is not the characteristics of an effective decision procedure ?
Correct formulation of the Rule U.I. (Universal Instantiation) is ........... .
Law of contradiction states that :
Characteristics of an Axiomatic systems are ................. .
(1) Consistency
(2) Completeness
(3) Independence
(4) Contingent
Correct symbolization of the following proposition is — “All successful politicians and orators are hard-working”.
If the statement ‘p’ is true and the statement ‘q’ is false, the truth value of the statements ‘p ≡ ~ q’ and ‘~ q ⊃ ~ p’ are :
In the ranking of a competitive examination Vishal was above Vijay but below Shyam. Mohan was above Shyam but below Rohan. Vijay was between Vishal and Ashok. Who is third from the top ?
Ragini facing East walks 10 meter, then she turns to her left and walks 12 meter. Then she turns to her right in $45^o$ and walks 15 meter. Then, how much distance she has walked from the starting point and which direction is she facing now ?
In the Wason selection task for propositional reasoning, ‘participants develop a general idea of the rule, then construct examples that follow the rule’ is referred to as :
Important Questions from Deductive - Teaching
Match List I and List II and select the correct answer from the codes given below :
List I List II (a) ~ (p ∨ ~ p) (1) Identity (b) ~ (p • ~ p) (2) Contingency (c) ~ (p ⊃ q) (3) Tautology (d) p ⊃ p (4) Contradiction Codes :
(a) (b) (c) (d)
Which of the following is not the characteristics of an effective decision procedure ?
Correct formulation of the Rule U.I. (Universal Instantiation) is ........... .
Law of contradiction states that :
Characteristics of an Axiomatic systems are ................. .
(1) Consistency
(2) Completeness
(3) Independence
(4) Contingent
