Which of the following statements is not a tautology?

Step-by-step solution

p ∧ q ∧ r is subset of r , so p ∧ q ∧ r is a subset of ~ p ∨ ~ q ∨ r . Hence, p ∧ q ∧ r ⇒ ~ p ∨ ~ q ∨ r is a tautology. Similarly, p ∧ q ∧ r ⇒ ~ p ∧ ~ q ∨ r is a tautology because p ∧ q ∧ r is a subset of ~ p ∧ ~ q ∨ r Similarly, p ∧ ~ q ∧ r is a subset of ~ p ∨ q ∨ r . Hence, p ∧ ~ q ∧ r ⇒ ~ p ∨ q ∨ r is a tautology p ∧ q ∧ ~ r &#8