The water in a tank is pressurized by air, and the pressure is measured by a multi fluid manometer as shown in Fig. P1–42 Determine the gage pressure of air in the tank if h1 = 0.2 m, h2 = 0.3 m, and h3 = 0.46 m. Take the densities of water, oil, and mercury to be 1000 kg/m3, 850 kg/m3, and 13,600 kg/m3, respectively.