Question
Let p, q, r be three statements such that the truth value of (p q) (q r) is F. Then the truth values of p, q, r are respectively :
Options
Solution
Key Concepts and Formulas
- The implication is false only when is true and is false.
- The conjunction is true only when both and are true.
- The disjunction is false only when both and are false.
- The negation of a true statement is false, and the negation of a false statement is true.
Step-by-Step Solution
Step 1: Analyze the given information.
We are given that is false. We need to determine the truth values of , , and .
Step 2: Apply the implication rule.
Since the implication is false, it must be the case that the antecedent is true and the consequent is false.
Step 3: Determine the truth values of and .
Since is true, both and must be true.
Step 4: Determine the truth value of .
Since is true, its negation is false.
Step 5: Determine the truth value of .
Since is false, and we know that is false, then must also be false.
Step 6: Summarize the truth values of , , and .
We have found that is true, is true, and is false. Therefore, the truth values of are T, T, F respectively.
Common Mistakes & Tips
- Remember the truth table for implication. is only false when A is true and B is false.
- Be careful with negations. If is true, then is false, and vice versa.
- It is useful to write out the truth tables for AND, OR, NOT, and IMPLICATION.
Summary
We are given that is false. This means that must be true and must be false. Since is true, both and must be true. Since is true, is false. Since is false and is false, must also be false. Therefore, is true, is true, and is false.
Final Answer
The final answer is \boxed{T, T, F}, which corresponds to option (D).