1. By drawing up appropriate truth tables, determine, for each pair of compound statements below, whether or not each one of the pair is logically equivalent to the other one of the pair. \text { (a) }(P \wedge Q) \vee R \text { and } P \wedge(Q \vee R) \text {. } \text { (b) } P \vee R \text { and } \neg P \Rightarrow R \text {. }