# Competitive Exams: Philosphy MCQs (Practice-Test 26 of 90)

1. Which one of the following is deduced from (~pq) [ (r. s) -p]. r

1. ~ q

2. ~ q-r

3. ~ s

4. r-s

2. Following is a normal proof of validity:

1. p- (q. r)

2. (p-r) (q-s)./-~ r-s

3. (p-r) (q-r).

4. p-q

5. r-s

6. ~ r-s

Which of the following sequence of rules has been used to derice the conclusion from lines 3 − 5?

1. Importation, Simplification, Constructive Dilemma, Definition of Implication

2. Distribution, Addition, Constructive Dilemma, Disjunctive Syllogism

3. Importation, Simplification, Hypothetical Syllogism, Disjunctive Syllogism

4. Distribution, Simplification

Constructive Dilemma, Definition of

Implication

3. Which one of the following statements follows from the proposition ‘Logic is difficult’

1. Assuming either that logic is difficult or that the text is not readable, Alfred will pass only if he concentrates

2. Logic is difficult if and only if it is not difficult

3. Unless logic is difficult, Alfred will pass if he concentrates

4. Logic is difficult just in case Alfred will pass if he concentrates