Calculate the cost of lime and soda required for softening 1 million litres of water containing: (MgHCO3)2 = 73 mg/L; MgSO4 = 120 mg/L; CaSO4 = 68 mg/L; CaCl2 = 111 mg/L. The cost of lime of 80% purity is Rs. 200 per metric ton and that of soda of 90% purity is Rs. 12,000 per metric ton.