Which symbol represents the disjunction in truth tables as given?

Which symbol represents the disjunction in truth tables as given?

• A. P and Q
• B. P or Q
• C. Not Q -> Not P
• D. P -> Q

Answer: (B)

Disjunction is the logical OR. In truth tables, P ∨ Q is true in every case except when both P and Q are false. So the expression that represents the disjunction is “P or Q,” since its truth table shows true when at least one of the propositions is true (F,F → F; F,T → T; T,F → T; T,T → T). The symbol most commonly used for this connective is OR (often written as ∨). The other options correspond to different connectives: “P and Q” is conjunction (true only when both are true), “P -> Q” is a conditional (false only when P is true and Q is false), and “Not Q -> Not P” is the contrapositive of the conditional P -> Q, not disjunction.

Disjunction is the logical OR. In truth tables, P ∨ Q is true in every case except when both P and Q are false. So the expression that represents the disjunction is “P or Q,” since its truth table shows true when at least one of the propositions is true (F,F → F; F,T → T; T,F → T; T,T → T). The symbol most commonly used for this connective is OR (often written as ∨). The other options correspond to different connectives: “P and Q” is conjunction (true only when both are true), “P -> Q” is a conditional (false only when P is true and Q is false), and “Not Q -> Not P” is the contrapositive of the conditional P -> Q, not disjunction.