Q1: [2 marks] Construct truth-tables for the following formulas, and decide whether each is a or contingent: tautology, contradiction, (p V q) a) (р ^q) b)-(pA)(q>p) Q2: [2 marks] Use truth-tables to determine whether the following sets of formulas are consistent or inconsistent. a) {p, (-р V q), -q} b) {(-p ** (р^q)), -а} Q3: [1 mark] Use a truth-table to determine whether the following argument is valid or invalid. (-Pуд), (q —> г), (s — р) :. (8 —> т)