solve in 60 mins I will thumb up

Water flows in an annular region between two coaxial cylinders, as shown in the figure, with the radius of R;=7 cm for the inner cylinder and the radius of Ro=11 cm for the outer cylinder. The inner cylinder is a rigid cylinder with benzoic acid cast on it. While water moves in the annular region, benzoic acid is dissolved from the surface of the inner cylinder into water. Water with benzoic acid concentration of 20 mg/L enters into the annular region at 40C with density of 0.9922 g/cm. The average Sherwood number is 87.2 and the volumetric flow rate of water is 2.72 L/min. The viscosities of water at 40C and 25C are 0.006527 and 0.0089 poise, respectively. Diffusion coefficient of benzoic acid in water at 25C is 9.18x10-6 cm/s. The solubility of benzoic acid in water is 5510 mg/L. What will be the outlet concentration of the benzoic acid in water (mg/L) if the length of the coaxial cylinders is 60 cm? NOTE: The characteristic dimension of this annular coaxial cylinders is the equivalent diameter of the annular region of the coaxial cylinders. NOTE: Clearly state all assumptions you make. You must show the details of your solution including the schematic diagram of the system and control volumes for each material balance. Marks will be deducted if the solution steps are not shown. The black tube is the inner cylinder, cast with benzoic acid (shown with blue color) on its surface. Liquid moves between the two cylinders (the annular region). Outer cylinder Inner cylinder cast with benzoic acid