Determine Whether the Given Argument Is Valid or Invalid

question 287

Multiple Choice

determine whether the given argument is valid or invalid. If it is invalid, select a counterexample.
-1. (∃x) (Px • Qx)
2) (∃x) (Px • Rx)
3) (∀x) (Qx ⊃ Sx)
4) (∀x) (Rx ⊃ Tx) / (∃x) (Px • Sx) • (∃x) (Px • Tx)

• A) Valid
• B) Invalid. Counterexample in a domain of 1 member, in which:
• Pa: True Qa: True Ra: True Sa: True Ta: True
• C) Invalid. Counterexample in a domain of 1 member, in which:
• Pa: False Qa: True Ra: True Sa: True Ta: True
• D) Invalid. Counterexample in a domain of 1 member, in which:
• Pa: True Qa: True Ra: False Sa: True Ta: True
• E) Invalid. Counterexample in a domain of 1 member, in which:
• Pa: True Qa: True Ra: True Sa: False Ta: True

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Definitions:

Insight Therapy

A form of psychotherapy focusing on the patient's self-awareness and understanding of the origins and meanings of their thoughts, feelings, and behaviors.

Psychotherapy

A method of treating mental health problems through talking with a psychiatrist, psychologist, or other mental health provider.

Behavior Therapy

A type of psychotherapy that focuses on changing undesirable behaviors through conditioning techniques and environmental changes.

Biomedical Therapy

A form of treatment for psychological disorders that is focused on understanding and treating the biological basis of the disorder, often involving medication or medical procedures.