Use the truth table method to evaluate the following arguments. For each, say whether the argument is valid or invalid. If the argument is valid, find and construct the tautology

based on the valid argument form. If the argument is invalid, give truth-value assignments (i.e. 'p is true/false') for each variable that could be used to construct a counterexample. If there are multiple possibilities,just give one. (15 points each) 1. pvq \text { 2. } p \Longrightarrow r \text { 3. } q \Longrightarrow r \therefore 4 . r \text { 1. }(p \wedge q) \Longrightarrow r \text { 2. } p \vee q \therefore 3 . r