Entailment again

Use truth-tables to determine whether the following inferences are correct:

1. ((P $\wedge$ Q) $\rightarrow$ R) $\models$ (P $\wedge$ Q)
2. ((P $\wedge$ $\neg$P) $\rightarrow$ Q) $\models$ $\neg$Q
3. $\models$ ((P $\rightarrow$ Q) $\vee$ P)
4. $\neg$(P $\wedge$ $\neg$P) $\models$