The surface of water in a water tank of cross section area \(750 \, \text{cm}^2\) on the top of a house is \(h \, \text{m}\) above the tap level. The speed of water coming out through the tap of cross section area \(500 \, \text{mm}^2\) is \(30 \, \text{cm/s}\). At that instant, \(\frac{dh}{dt}\) is \(x \times 10^{-3} \, \text{m/s}\). The value of \(x\) will be _________.