S={2,a,{3},4} and R={{a},3,4,1} indicate whether the following are true or false
1) $\varnothing \subset R$
2)$\varnothing \subseteq \left \{ \left \{ a \right \} \right \}\subseteq R\subseteq E$ E=Universal Set
3) $\left \{ \varnothing \right \}\subseteq S$
4) $\varnothing \in R$
I think 1,2 are true and 3 is false and about 4 nothing is clear