[tex]\bf \textit{volume of a cylinder}\\\\ V=\pi r^2 h~~ \begin{cases} r=radius\\ h=height\\[-0.5em] \hrulefill\\ r=6\\ h=15 \end{cases}\implies \begin{array}{llll} V=\pi (6)^2(15)\implies V=540\pi \\\\\\ V\approx 1696.46 \end{array}[/tex]
notice, the cup can take that much in cm³, so it can surely take 1620 just fine.
