An open concrete tank is internally 1m wide2m long and1.5m deep,the concrete being 10m thick,calculate the capacity of the tank in litres and the volume of concrete used in m cube
interior: 1*2*1.5 = 3 m^3 = 3000L
exterior (really? 10m thick? ok, ...): (1+20)(2+20)(1.5+10) = 5313 m^3
concrete: exterior - interior = 5310 m^3