A city is considering a 3 stage membrane system to treat brackish groundwater at its water treatment plant, WTP (Qf=1000m^3/d, Cf=2000mg/L TDS). Each stage can perform 60 % water recovery (Qp/Cf) and 90% salt rejection (1-Cp/Cf) A) What is the overall product water recovery and salt rejection b)what is final product water flow rate (m^3/day) and quality in terms of TDS (mg/L). c) how much concentrate needs disposal (m^3/d) and how salty is it (mg/L) ?