Hand written solution required

PROBLEM The tank in the Figure contains two fluids y = 1300 N/me 12 - 900 N/m3 the third (top) layer is occupied by air (small specific weight). The thickness of the layers is, respectively. hi - 4.00 m , hz - 3.00 m. h3 - 3.50 m. The height of fluid measured in the piezometric pipe is h = 9.10 m and refers to the pressure in correspondence of the tank bottom. On the lateral wall there is a gate whose size are a =2:50 m x L = 4.00 m; the distance between the bottom of the gate and the bottom of the tank is ha = 1:00 m. hi -3.50 m hi = 3.00 m h-9.10m a -2.50 m he 4.00m 1.00 mi L -14.00 m