Mohammad Hossein Jafari, Ali Reza Madadi University of Tabriz, University of Tabriz
Abstract : Let $G$ be a finite group and $m$ a divisor of $|G|.$ We prove that $G$ has at least $\tau(m)$ cyclic subgroups whose orders divide $m$, where $\tau(m)$ is the number of divisors of $m.$