2. The water in a tank is pressurized by air, and the pressure is measured by a multi-fluid

manometer as shown in Figure 2. Determine the gage pressure of air in the tank if h₁ =

0.2 m, h₂ = 0.3 m, and h3 = 0.4 m. Take the densities of water, oil, and mercury to be

1000 kg/m³, 850 kg/m³, and 13,600 kg/m³, respectively.