A problem of Erdős on Abelian groups
The following theorem is proved. If \(a_ 1,a_ 2,...,a_ n\) are nonzero elements in \({\mathbb{Z}}_ n\), and are not all equal, then \(\epsilon_ 1a_ 1+\epsilon_ 2a_ 2+...+\epsilon_ na_ n=0\) has at least n solutions with \(\epsilon_ i=0\) or 1.
scientific article; zbMATH DE number 4047955