Question 3
Let $n$ be a given integer greater than $2$, and let $V_n$ be the set of integers $1+kn$, where $k=1,2,\ldots$. A number $m\in V_n$ is called indecomposable in $V_n$ if there do not exist numbers $p,q\in V_n$ such that $pq=m$. Prove that there exists a number $r\in V_n$ that can be expressed as the product of elements indecomposable in $V_n$ in more than one way. (Expressions that differ only in order of the elements of $V_n$ will be considered the same.)