If it takes 5 minutes to fill a 15 litre bucket from a water tap of diameter $\frac{2}{\sqrt{\pi }}$   cm, then the Reynolds number for the flows is (density of water $={10}^{3}kg/m^3$ and viscosity of water $={10}^{-3}Pa.s$ ) close to 

For liquid flow in a pipeline, Reynolds number is given as
$R=\frac{\rho vD}{\eta }$
v$\to$flow velocity
 $\rho$$\to$density
D$\to$internal daintier of pipeline
The volume flow rate of water through tap is given as
$Av=\frac{V}{t}=\frac{15\times {10}^3}{5\times 60}c{m}^3/s$
Av-Cross–section area of tap
$\Rightarrow v=\frac{15\times {10}^3}{300\times \pi \times {\left(\frac{1}{\sqrt{\pi }}\right)}^2}=50cm/s=0.5m/s$
$\Rightarrow$Reynolds number is given as
$R=\frac{\rho vd}{\eta }=\frac{{10}^3\times 0.5\times \frac{2}{\sqrt{3.14}}\times {10}^{-2}}{{10}^{-3}}$

$R=\frac{1}{\sqrt{3.14}}\times {10}^4=5641$