Question

Write down all the subsets of the given set: {a}

Answer 1

we know, if two set e.g., A and B are given and we can say $A\subset B$ only when all elements of set A are elements of set B.

now, if we have to write all the subsets of tbe given set A. then first of all, you should find out total number of subset can be possible of set A. for example if A = {a, b, c} then, number of elements in A = 3 so, total number of subsets = 2³ = 8
and e.g., $\emptyset$,{a}, {b}, {c}, {a, b}, {a, c}, {b, c} , {a, b, c}

now come to the question,
here given set : {a}
number of elements , n = 1
so, total number of subset of given set = 2¹ = 2
therefore, subsets are $\emptyset$, {a}