The cylindrical tube of a spray pump has a radius,H, one end of which has n fine holes, each of radius r. If the speed of flow of the liquid in the tube is y, the speed of ejection of the liquid through the hole is 

Cross-sectional area of the tube $=\mathrm{A}={\mathrm{\pi R}}^2$
 speed of flow of liquid in the tube = V
cross-sectional area of each hole $={\mathrm{\pi r}}^2$
cross-sectional area of n hole $={\mathrm{n\pi r}}^2$
kt the speed of ejection of liquid through the hole = v
According to continuity equation 
$$\begin{gathered} \mathrm{aV}=\mathrm{AV} \\ \left({\mathrm{n\pi r}}^2\right)\mathrm{V}=\left({\mathrm{\pi R}}^2\right)\mathrm{V} \\ \mathrm{V}=\frac{\mathrm{V}}{\mathrm{n}}{\left(\frac{\mathrm{R}}{\mathrm{r}}\right)}^2 \end{gathered}$$