A mixture of water (density 1000 kg/m3) and oil (density 800 kg/m3) is flowing through a tube of diameter 2 cm with a velocity of 4 m/s. The mass flow rate is measured to be 1.068 kg/s. Determine (a) the density of the liquid mixture, (b) the percentage of oil in the mixture by mass. Assume liquids to be incompressible.