A venturi meter (venturi coefficient $C_v = 0.98$) is installed in a pipe of inner diameter 50 mm. Water (density 1000 kg m$^{-3}$) flows through the pipe. The pressure drop across the venturi meter is 50 kPa. If the venturi throat diameter is 20 mm, the estimated flow rate is \(\underline{\hspace{2cm}}\) $\times 10^{-3}$ m$^{3}$ s$^{-1}$ (rounded off to two decimal places).