Question 1
Given: p ∨ q, ¬p
What can you validly derive?
Rule: Disjunctive Syllogism
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
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Ready to master Natural Deduction? This timed practice ⚡ worksheet (6/10) presents 20 intermediate-advanced-level challenges. Focus area: speed building. Learn to solve natural deduction tricks, handle natural deduction shortcut methods, and perfect natural deduction bank exam questions with our step-by-step solutions.
What you'll learn in this worksheet:
- Understand the logic behind natural deduction shortcut methods
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Your progress through Natural Deduction
Worksheet 6 of 10 (55% complete)
Question 2
Given: p → q, ¬q
What can you validly derive?
Rule: Modus Tollens
If P → Q and Q is false, then P must be false.
Answer: ¬p
If P → Q and Q is false, then P must be false.
Answer: ¬p
Question 3
Given: p ∨ q, ¬p
What can you validly derive?
Rule: Disjunctive Syllogism
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
Question 4
Given: p, q
What can you validly derive?
Rule: Conjunction Introduction (∧-intro)
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
Question 5
Given: p, q
What can you validly derive?
Rule: Conjunction Introduction (∧-intro)
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
Question 6
Given: p ∨ q, ¬p
What can you validly derive?
Rule: Disjunctive Syllogism
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
Question 7
Given: p ∨ q, ¬p
What can you validly derive?
Rule: Disjunctive Syllogism
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
Question 8
Given: p
What can you validly derive?
Rule: Disjunction Introduction (∨-intro)
If P is true, then P ∨ Q is true for any Q (addition rule).
Answer: p ∨ q
If P is true, then P ∨ Q is true for any Q (addition rule).
Answer: p ∨ q
Question 9
Given: p
What can you validly derive?
Rule: Disjunction Introduction (∨-intro)
If P is true, then P ∨ Q is true for any Q (addition rule).
Answer: p ∨ q
If P is true, then P ∨ Q is true for any Q (addition rule).
Answer: p ∨ q
Question 10
Given: p → q, ¬q
What can you validly derive?
Rule: Modus Tollens
If P → Q and Q is false, then P must be false.
Answer: ¬p
If P → Q and Q is false, then P must be false.
Answer: ¬p
Question 11
Given: p ∧ q
What can you validly derive?
Rule: Simplification (∧-elimination)
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
Question 12
Given: p ∧ q
What can you validly derive?
Rule: Simplification (∧-elimination)
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
Question 13
Given: p, q
What can you validly derive?
Rule: Conjunction Introduction (∧-intro)
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
Question 14
Given: p → q, ¬q
What can you validly derive?
Rule: Modus Tollens
If P → Q and Q is false, then P must be false.
Answer: ¬p
If P → Q and Q is false, then P must be false.
Answer: ¬p
Question 15
Given: p ∧ q
What can you validly derive?
Rule: Simplification (∧-elimination)
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
Question 16
Given: p → q, ¬q
What can you validly derive?
Rule: Modus Tollens
If P → Q and Q is false, then P must be false.
Answer: ¬p
If P → Q and Q is false, then P must be false.
Answer: ¬p
Question 17
Given: p ∨ q, ¬p
What can you validly derive?
Rule: Disjunctive Syllogism
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
If P ∨ Q is true and P is false, then Q must be true.
Answer: q
Question 18
Given: p ∧ q
What can you validly derive?
Rule: Simplification (∧-elimination)
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
From a conjunction P ∧ Q, you can derive P (or Q) alone.
Answer: p
Question 19
Given: p, q
What can you validly derive?
Rule: Conjunction Introduction (∧-intro)
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
If you have P and you have Q, you can combine them into P ∧ Q.
Answer: p ∧ q
Question 20
Given: p → q, ¬q
What can you validly derive?
Rule: Modus Tollens
If P → Q and Q is false, then P must be false.
Answer: ¬p
If P → Q and Q is false, then P must be false.
Answer: ¬p
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