A sufficient conditon for solvability of finite groups

Abstract

The following theorem is proved: Let $G$ be a finite group and $\pi_e(G)$ be the set of element orders in $G$. If $\pi_e(G) \cap \{2\}=\emptyset$; or $\pi_e(G) \cap \{3, 4\}=\emptyset$; or $\pi_e(G) \cap \{3,5\}=\emptyset$, then $G$ is solvable. Moreover, using the intersection with $\pi_e(G)$ being empty set to judge $G$ is solvable or not, only the above three cases.