Prove have a set with exactly 12 subset

Question

How to do this question?

Is there a set with exactly 12 subsets? Explain

Answer 1

Pauline, the number of subsets of a finite set $X$ is given by $2^{|X|}$, where $|X|$ is the number of elements contained in $X$. Since there is no positive integer $k$ satisfying $2^k = 12$, the answer to your question is no.