Solve $$\int\limits_{0}^{3}\int\limits_{-\sqrt{9-y^2}}^{\sqrt{9-y^2}}\int\limits_{0}^{9-3\sqrt{x^2+y^2}}dzdxdy.$$
Update: The problem is setting up the integral. What I have tried was $$\int\limits_{0}^{\pi}\int\limits_{-3}^{3}\int\limits_{0}^{9-3r}dzrdrd\theta.$$ It gave me $54\pi$ and I don't think it's right.