pls answer 29th question

$$\begin{gathered} \mathrm{Volume} \mathrm{of} \mathrm{the} \mathrm{water} \mathrm{filled} \mathrm{in} 1 \sec = 15 {\mathrm{cm}}^3 \\ \mathrm{Volume} \mathrm{of} \mathrm{the} \mathrm{water} \mathrm{filled} \mathrm{in} \mathrm{y} \sec = 15\mathrm{y} {\mathrm{cm}}^3 \\ \mathrm{Now}, \mathrm{according} \mathrm{to} \mathrm{question} : \\ \mathrm{x} = 15\mathrm{y} \end{gathered}$$

GRAPH :





From the graph, we observe that,

Volume of the water filled in 9 sec = 135 cm³