Hello. Chould you teach me how I can solve the problem, please?

(25) Hlaw many grams of (lacl must be addod to (66ml of water so that by mixing it with lotml of NaCl solution at a concentration of 153.9mmol/l the saline is prepared. (we heslect thevolume of salt). (33) How much water (in ml ) it is necessary to add to ( 94ml o of saline to prepare a solution of final density concentration 04%