1) 3 E {1,2,3}

2) 1 is not a subset of {1}

3){2} is not a subset of {1,{2},{3}}

4){1} is a subset of of {1,{2}}

1. 3 is an element of the set

2. 1 is not a subset of the set, just an element

3. {2} is a subset of the set

4. {1} is not a subset of the set,

if the set were{{1},{2}} then {1} would be a subset of it