20. Solving a chemistry problem

70. Industrial wastewater contains: a) 42 g/m3 of magnesium sulfate; b) 6.0 g/m3 sodium phosphate; c) 12 g/m3 manganese (II) chloride; d) 16 g/m3 zinc chloride. How many times should the effluents be diluted with water so that the sanitary standards for the content of these harmful wastes in the water are not violated? The maximum permissible concentrations of salts in water are as follows: magnesium sulfate - 1.7 * 10-4 mol / l; sodium phosphate - 3.0 * 10-6 mol / l; manganese (II) chloride - 1.6 * 10-6 mol / l; zinc chloride - 7.3 * 10-7 mol / l.