Question

Determine whether the following statement patterns are tautologies, contradictions or contingencies.
(i) (p → q) ∧ (p ∧ ∼q)
(ii) (p ∧ q) ∨ (∼p ∧ q) ∨ (p ∧ ∼q) ∨ (∼p ∧ ∼q)
(iii) [p ∧ (p → q)] → q
(iv) [(p ∨ ∼q) ∨ (∼p ∧ q)] ∧ r