Finite groups with mostly involuted cyclic subgroups

Abstract

Let $G$ be a finite group. Let $C(G)$ be the set of cyclic subgroups of $G$, $c(G)=|C(G)|$ and $i(G)=\left|\{x\in G : x^{2}=e\}\right|$. In this article, we classify finite groups with $i(G)=c(G)-r$ for $r\in \{0,1,2\}$ and prove that the range of the function given by $\beta(G)=\frac{i(G)}{c(G)}$ is dense in $[0,1]$. We also answer an open question posed by Gao and Shen in `Finite groups with many cyclic subgroups'.