In these exercises your challenge is to distinguish deductively valid arguments from deductively invalid argument. The following concepts should help when determining each answer:

Modus Ponens: A Hypothetical Syllogism that reaches it conclusion by affirming the antecedent of a conditional statement: If X, then Y. X. Therefore, Y. It is deductively valid.

Modus Tollens: A Hypothetical Syllogism that reaches it conclusion by denying the consequent of a conditional statement: If X, then Y. Not Y. Therefore not X. It is deductively valid.

Affirming the Consequence: A Hypothetical Syllogism that reaches it conclusion by affirming the consequent of a conditional statement: If X, then Y. Y. Therefore, X. It is deductively invalid.

Denying the Antecedent: A Hypothetical Syllogism that reaches it conclusion by denying the antecedent of a conditional statement: If X, then Y. Not x. Therefore, not Y. It is deductively invalid.

Hypothetical "Chain" Argument: A Hypothetical Syllogism that takes the form: If X, then Y. If Y, then Z. Therefore, if X, then Z. It is deductively valid.

Disjunctive Syllogism: A syllogism that reaches its conclusion by denying the component of a disjunctive statement: X or Y. Not X. Therefore Y.