A river having a volumetric flow rate of 25.0 m3/s and containing 300. ppm total dissolved salts (considered to be conservative) receives a steady agricultural discharge of 5.00 m3/s carrying 2000. mg/L of total dissolved salts (from fertilizer etc). The agricultural discharge quickly becomes mixed in the river. A downstream municipality withdraws the mixed river water and blends it with enough clean water from a pristine source (zero ppm total dissolved salts) to be able to deliver water having no more than 400. ppm total dissolved salts to its customers. What mixture ratio of clean water to river water is required to be used by the municipality to meet its water quality target of 400. ppm