EN
Let $c_{q}(n)$ be the Ramanujan sum, i.e. $c_{q}(n) = ∑_{d|(q,n)} dμ(q/d)$, where μ is the Möbius function. In a paper of Chan and Kumchev (2012), asymptotic formulas for $∑_{n≤y}(∑_{q≤x} c_{q}(n))^{k}$ (k = 1,2) are obtained. As an analogous problem, we evaluate $∑_{n≤y}(∑_{n≤x} ĉ_{q}(n))^{k}$ (k = 1,2), where $ĉ_{q}(n) := ∑_{d|(q,n)}d|μ(q/d)|$.